From b013f75eef0ffa77db9c74f85c82028ce4b07f1c Mon Sep 17 00:00:00 2001
From: ralf <rb@egroupware.org>
Date: Mon, 24 Jul 2023 17:08:05 +0200
Subject: [PATCH] * Calendar: new REST API to read, create, modify and delete
 events, see
 https://github.com/EGroupware/egroupware/blob/master/doc/REST-CalDAV-CardDAV/Calendar.md

---
 api/src/CalDAV/JsCalendar.php                | 167 +++++-
 calendar/inc/class.calendar_bo.inc.php       |   6 +-
 calendar/inc/class.calendar_groupdav.inc.php |  52 +-
 calendar/inc/class.calendar_rrule.inc.php    |   4 +-
 doc/REST-CalDAV-CardDAV/Addressbook.md       | 504 ++++++++++++++++++
 doc/REST-CalDAV-CardDAV/Calendar.md          | 383 ++++++++++++++
 doc/REST-CalDAV-CardDAV/README.md            | 505 +------------------
 7 files changed, 1083 insertions(+), 538 deletions(-)
 create mode 100644 doc/REST-CalDAV-CardDAV/Addressbook.md
 create mode 100644 doc/REST-CalDAV-CardDAV/Calendar.md

diff --git a/api/src/CalDAV/JsCalendar.php b/api/src/CalDAV/JsCalendar.php
index 8bf5f537c0..f7484bfc41 100644
--- a/api/src/CalDAV/JsCalendar.php
+++ b/api/src/CalDAV/JsCalendar.php
@@ -33,16 +33,17 @@ class JsCalendar
 	 *
 	 * @param int|array $event
 	 * @param bool|"pretty" $encode=true true: JSON encode, "pretty": JSON encode with pretty-print, false: return raw data e.g. from listing
+	 * @param ?array $exceptions=null
 	 * @return string|array
 	 * @throws Api\Exception\NotFound
 	 */
-	public static function getJsEvent($event, $encode=true)
+	public static function JsEvent($event, $encode=true, array $exceptions=[])
 	{
 		if (is_scalar($event) && !($event = self::getCalendar()->read($event)))
 		{
 			throw new Api\Exception\NotFound();
 		}
-		$data = array_filter([
+		$data = [
 			self::AT_TYPE => self::TYPE_EVENT,
 			'prodId' => 'EGroupware Calendar '.$GLOBALS['egw_info']['apps']['api']['version'],
 			'uid' => self::uid($event['uid']),
@@ -54,16 +55,25 @@ class JsCalendar
 			'timeZone' => $event['tzid'],
 			'showWithoutTime' => $event['whole_day'],
 			'duration' => self::Duration($event['start'], $event['end'], $event['whole_day']),
+			'recurrenceRules' => null,
+			'recurrenceOverrides' => null,
 			'freeBusyStatus' => $event['non_blocking'] ? 'free' : null,   // default is busy
 			'description' => $event['description'],
 			'participants' => self::Participants($event),
+			'alerts' => self::Alerts($event['alarm']),
 			'status' => empty($event['deleted']) ? 'confirmed' : 'cancelled',   // we have no "tentative" event-status (only participants)!
 			'priority' => self::Priority($event['priority']),
 			'categories' => self::categories($event['category']),
 			'privacy' => $event['public'] ? 'public' : 'private',
-			'alerts' => self::Alerts($event['alarms']),
 			'egroupware.org:customfields' => self::customfields($event),
-		]+self::Locations($event)+self::Recurrence($event));
+		] + self::Locations($event);
+
+		if (!empty($event['recur_type']))
+		{
+			$data = array_merge($data, self::Recurrence($event, $data, $exceptions));
+		}
+		$data = array_filter($data);
+
 		if ($encode)
 		{
 			return Api\CalDAV::json_encode($data, $encode === "pretty");
@@ -149,7 +159,13 @@ class JsCalendar
 						break;
 
 					case 'alerts':
-						$event['alarms'] = self::parseAlerts($value);
+						throw new \Exception('Creating or modifying alerts is NOT (yet) implemented!');
+						break;
+
+					case 'recurrenceRules':
+					case 'recurrenceOverrides':
+					case 'excludedRecurrenceRules':
+						throw new \Exception('Creating or modifying recurring events is NOT (yet) implemented!');
 						break;
 
 					case 'categories':
@@ -174,6 +190,13 @@ class JsCalendar
 		catch (\Throwable $e) {
 			self::handleExceptions($e, 'JsCalendar Event', $name, $value);
 		}
+
+		// if no participant given add current user as CHAIR to the event
+		if (empty($event['participants']))
+		{
+			$event['participants'][$GLOBALS['egw_info']['user']['account_id']] = 'ACHAIR';
+		}
+
 		return $event;
 	}
 
@@ -538,13 +561,15 @@ class JsCalendar
 				$info = self::getCalendar()->resource_info($uid) ?: [];
 				switch($info['type'] ?? $info['app'])
 				{
-					case 'user':
+					case 'e':   // email
+					case 'c':   // contact
+					case 'u':   // user
 						$info['kind'] = 'individual';
 						break;
-					case 'group':
+					case 'g':
 						$info['kind'] = 'group';
 						break;
-					case 'resources':
+					case 'r':
 						$info['kind'] = Api\CalDAV\Principals::resource_is_location($user_id) ? 'location' : 'resource';
 						break;
 				}
@@ -552,7 +577,7 @@ class JsCalendar
 			catch (\Exception $e) {
 				$info = [];
 			}
-			$participant = [
+			$participant = array_filter([
 				self::AT_TYPE => self::TYPE_PARTICIPANT,
 				'name' => $info['name'] ?? null,
 				'email' => $info['email'] ?? null,
@@ -565,7 +590,7 @@ class JsCalendar
 					'informational' => $role === 'NON-PARTICIPANT',
 				]),
 				'participationStatus' => $status2jscal[$status],
-			];
+			]);
 			$participants[$uid] = $participant;
 		}
 
@@ -612,22 +637,122 @@ class JsCalendar
 		return $priority_egw2jscal[$priority];
 	}
 
+	const TYPE_RECURRENCE_RULE = 'RecurrenceRule';
+	const TYPE_NDAY = 'NDay';
+
 	/**
 	 * Return recurrence properties: recurrenceId, recurrenceRules, recurrenceOverrides, ...
 	 *
-	 * @TODO
+	 * EGroupware only supports a subset of iCal recurrence rules (e.g. only byDay and byMonthDay, no other by-types)!
+	 *
 	 * @param array $event
+	 * @param array $data JSCalendar representation of event to calculate overrides
+	 * @param array $exceptions exceptions
 	 * @return array
 	 */
-	protected static function Recurrence(array $event)
+	protected static function Recurrence(array $event, array $data, array $exceptions=[])
 	{
-		return [];
+		if (empty($event['recur_type']))
+		{
+			return [];  // non-recurring event
+		}
+		$rriter = \calendar_rrule::event2rrule($event, false);
+		$rrule = $rriter->generate_rrule('2.0');
+		$rule = array_filter([
+			self::AT_TYPE => self::TYPE_RECURRENCE_RULE,
+			'frequency' => strtolower($rrule['FREQ']),
+			'interval' => $rrule['INTERVAL'] ?? null,
+			'until' => empty($rrule['UNTIL']) ? null : self::DateTime($rrule['UNTIL'], $event['tzid']),
+		]);
+		if (!empty($GLOBALS['egw_info']['user']['preferences']['calendar']['weekdaystarts']) &&
+			$GLOBALS['egw_info']['user']['preferences']['calendar']['weekdaystarts'] !== 'Monday')
+		{
+			$rule['firstDayOfWeek'] = strtolower(substr($GLOBALS['egw_info']['user']['preferences']['calendar']['weekdaystarts'], 0, 2));
+		}
+		if (!empty($rrule['BYDAY']))
+		{
+			$rule['byDay'] = array_filter([
+				self::AT_TYPE => self::TYPE_NDAY,
+				'day' => strtolower(substr($rrule['BYDAY'], $rriter->monthly_byday_num ? strlen((string)$rriter->monthly_byday_num) : 0)),
+				'nthOfPeriod' => $rriter->monthly_byday_num,
+			]);
+		}
+		elseif (!empty($rrule['BYMONTHDAY']))
+		{
+			$rule['byMonthDay'] = [$rrule['BYMONTHDAY']];   // EGroupware supports only a single day!
+		}
+
+		$overrides = [];
+		// adding excludes to the overrides
+		if (!empty($event['recur_exception']))
+		{
+			foreach ($event['recur_exception'] as $timestamp)
+			{
+				$ex_date = new Api\DateTime($timestamp, Api\DateTime::$server_timezone);
+				if (!empty($event['whole_day']))
+				{
+					$ex_date->setTime(0, 0, 0);
+				}
+				$overrides[self::DateTime($ex_date, $event['tzid'])] = [
+					'excluded' => true,
+				];
+			}
+		}
+
+		// adding exceptions to the overrides
+		foreach($exceptions as $exception)
+		{
+			$overrides[self::DateTime($exception['recurrence'], $event['tzid'])] = self::getPatch(self::JsEvent($exception, false), $data);
+		}
+
+		return array_filter([
+			'recurrenceRules' => [$rule],
+			'recurrenceOverrides' => $overrides,
+		]);
 	}
 
+	/**
+	 * Get patch from an event / recurrence compared to the master event
+	 *
+	 * @param array $event
+	 * @param array $master
+	 * @return array with modified attributes
+	 */
+	public static function getPatch(array $event, array $master=null)
+	{
+		if (!$master)
+		{
+			return $event;
+		}
+		// array_diff_assoc only reports values changed or set in $event for scalar values
+		$patch = array_diff_assoc($event, $master);
+
+		// we need to report unset / removed values
+		foreach($master as $name => $value)
+		{
+			if (isset($value) && !isset($event[$name]))
+			{
+				$patch[$name] = null;
+			}
+		}
+
+		// for non-scalar values, we have to call ourselves recursive
+		foreach($event as $name => $value)
+		{
+			if (is_array($value) && ($diff = self::getPatch($event[$name], $master[$name])))
+			{
+				$patch[$name] = $diff;
+			}
+		}
+		return $patch;
+	}
+
+	const TYPE_ALERT = 'Alert';
+	const TYPE_OFFSET_TRIGGER = 'OffsetTrigger';
+
 	/**
 	 * Return alerts object
 	 *
-	 * @TODO
 	 * @param array|null $alarms
 	 * @return array
 	 */
@@ -636,7 +761,19 @@ class JsCalendar
 		$alerts = [];
 		foreach($alarms ?? [] as $alarm)
 		{
-
+			if (!isset($alarm['offset']) || empty($alarm['all']) && $alarm['owner'] != $GLOBALS['egw_info']['user']['account_id'])
+			{
+				continue;   // do NOT show other users alarms
+			}
+			$alerts[$alarm['uid']] = array_filter([
+				self::AT_TYPE => self::TYPE_ALERT,
+				'trigger' => [
+					self::AT_TYPE => self::TYPE_OFFSET_TRIGGER,
+					'offset' => $alarm['offset'],
+				],
+				'acknowledged' => empty($alarm['attrs']['ACKNOWLEDGED']['value']) ? null :
+					self::UTCDateTime(new Api\DateTime($alarm['attrs']['ACKNOWLEDGED']['value'])),
+			]);
 		}
 		return $alerts;
 	}
diff --git a/calendar/inc/class.calendar_bo.inc.php b/calendar/inc/class.calendar_bo.inc.php
index 917942c708..3d27c566a2 100644
--- a/calendar/inc/class.calendar_bo.inc.php
+++ b/calendar/inc/class.calendar_bo.inc.php
@@ -1128,7 +1128,7 @@ class calendar_bo
 	}
 
 	/**
-	 * Inserts all repetions of $event in the timespan between $start and $end into $events
+	 * Inserts all repetitions of $event in the timespan between $start and $end into $events
 	 *
 	 * The new entries are just appended to $events, so $events is no longer sorted by startdate !!!
 	 *
@@ -2191,9 +2191,9 @@ class calendar_bo
 			$entry = $this->read($id, $recur_date, true, 'server');
 		}
 		$etag = $schedule_tag = $entry['id'].':'.$entry['etag'];
-		$etag .= ':'.$entry['modified'];
+		$etag .= ':'.Api\DateTime::user2server($entry['modified'], 'ts');
 
-		//error_log(__METHOD__ . "($entry[id],$client_share_uid_excpetions) entry=".array2string($entry)." --> etag=$etag");
+		//error_log(__METHOD__ . "($entry[id],$client_share_uid_exceptions) entry=".array2string($entry)." --> etag=$etag");
 		return $etag;
 	}
 
diff --git a/calendar/inc/class.calendar_groupdav.inc.php b/calendar/inc/class.calendar_groupdav.inc.php
index d74dfbb5f4..a0d1c9c724 100644
--- a/calendar/inc/class.calendar_groupdav.inc.php
+++ b/calendar/inc/class.calendar_groupdav.inc.php
@@ -383,10 +383,11 @@ class calendar_groupdav extends Api\CalDAV\Handler
 		$events = null;
 		$is_jscalendar = Api\CalDAV::isJSON();
 		for($chunk=0; (!$chunk || count($events) === self::CHUNK_SIZE) && // stop after we have not got a full chunk
-			($events =& $this->bo->search($filter+[
+			($events =& $this->bo->search([
 				'offset' => $chunk*self::CHUNK_SIZE,
 				'num_rows' => self::CHUNK_SIZE,
-			])); ++$chunk)
+				'date_format' => $is_jscalendar ? 'object' : 'ts',
+			]+$filter)); ++$chunk)
 		{
 			foreach($events as $event)
 			{
@@ -441,11 +442,10 @@ class calendar_groupdav extends Api\CalDAV\Handler
 				//error_log(__FILE__ . __METHOD__ . "Calendar Data : $calendar_data");
 				if ($calendar_data)
 				{
-					$content = $is_jscalendar ? Api\CalDAV\JsCalendar::getJsEvent($event, false) :
-						$this->iCal($event, $filter['users'],
+					$content = $this->iCal($event, $filter['users'],
 						strpos($path, '/inbox/') !== false ? 'REQUEST' : null,
 						!isset($calendar_data['children']['expand']) ? false :
-							($calendar_data['children']['expand']['attrs'] ?: true), $exceptions);
+							($calendar_data['children']['expand']['attrs'] ?: true), $exceptions, $is_jscalendar ? false : null);
 					$props['getcontentlength'] = bytes($is_jscalendar ? json_encode($content) : $content);
 					$props['calendar-data'] = Api\CalDAV::mkprop(Api\CalDAV::CALDAV,'calendar-data',$content);
 				}
@@ -578,10 +578,12 @@ class calendar_groupdav extends Api\CalDAV\Handler
 		}
 		if ($time)
 		{
-			$props['dtstamp'] = Api\CalDAV::mkprop(Api\CalDAV::CALENDARSERVER, 'dtstamp', gmdate('Ymd\\This\\Z', $time));
+			$dtstamp = Api\DateTime::to($time, 'object');
+			$dtstamp->setTimezone(new DateTimeZone('utc'));
+			$props['dtstamp'] = Api\CalDAV::mkprop(Api\CalDAV::CALENDARSERVER, 'dtstamp', $dtstamp->format('Ymd\\This\\Z'));
 		}
 		//error_log(__METHOD__."($user, $time) returning ".array2string($props));
-		return $props ? $props : '';
+		return $props ?: '';
 	}
 
 	/**
@@ -763,12 +765,12 @@ class calendar_groupdav extends Api\CalDAV\Handler
 		// jsEvent or iCal
 		if (($type=Api\CalDAV::isJSON()))
 		{
-			$options['data'] = Api\CalDAV\JsCalendar::getJsEvent($event, $type);
+			$options['data'] = $this->iCal($event, $user, strpos($options['path'], '/inbox/') !== false ? 'REQUEST' : null, false, null, $type);
 			$options['mimetype'] = Api\CalDAV\JsCalendar::MIME_TYPE_JSEVENT.';charset=utf-8';
 		}
 		else
 		{
-			$options['data'] = $this->iCal($event, $user, strpos($options['path'], '/inbox/') !== false ? 'REQUEST' : null);
+			$options['data'] = $this->iCal($event, $user, strpos($options['path'], '/inbox/') !== false ? 'REQUEST' : null, false, null);
 			$options['mimetype'] = 'text/calendar; charset=utf-8';
 		}
 		header('Content-Encoding: identity');
@@ -784,16 +786,17 @@ class calendar_groupdav extends Api\CalDAV\Handler
 	/**
 	 * Generate an iCal for the given event
 	 *
-	 * Taking into account virtual an real exceptions for recuring events
+	 * Taking into account virtual and real exceptions for recurring events
 	 *
 	 * @param array $event
 	 * @param int $user =null account_id of calendar to display
-	 * @param string $method =null eg. 'PUBLISH' for inbox, nothing anywhere else
+	 * @param string $method =null e.g. 'PUBLISH' for inbox, nothing anywhere else
 	 * @param boolean|array $expand =false true or array with values for 'start', 'end' to expand recurrences
 	 * @param array|null $events as returned by get_series() for !$expand (to not read them again)
-	 * @return string
+	 * @param bool|"pretty"|null $json null: iCal, false: return array with JSCalendar data, true+"pretty": return json-serialized JSCalendar
+	 * @return string|array array if $json === false
 	 */
-	private function iCal(array $event,$user=null, $method=null, $expand=false, array $events=null)
+	private function iCal(array $event,$user=null, $method=null, $expand=false, array $events=null, $json=null)
 	{
 		static $handler = null;
 		if (is_null($handler)) $handler = $this->_get_handler();
@@ -843,7 +846,7 @@ class calendar_groupdav extends Api\CalDAV\Handler
 			// pass in original event as master, as it has correct start-date even if first recurrence is an exception
 			if ($expand || !isset($events))
 			{
-				$events =& self::get_series($event['uid'], $this->bo, $expand, $user, $event);
+				$events =& self::get_series($event['uid'], $this->bo, $expand, $user, $event, isset($json) ? 'object' : 'server');
 			}
 			// as alarm is now only on next recurrence, set alarm from original event on master
 			if ($event['alarm']) $events[0]['alarm'] = $event['alarm'];
@@ -857,6 +860,10 @@ class calendar_groupdav extends Api\CalDAV\Handler
 				$events[0]['uid'] .= '-'.$event['id'];	// force a different uid
 			}
 		}
+		if (isset($json))
+		{
+			return Api\CalDAV\JsCalendar::JsEvent($events[0], $json, array_slice($events, 1));
+		}
 		return $handler->exportVCal($events, '2.0', $method);
 	}
 
@@ -872,7 +879,7 @@ class calendar_groupdav extends Api\CalDAV\Handler
 	 * @param array $master =null use provided event as master to fix wrong start-date if first recurrence is an exception
 	 * @return array
 	 */
-	private static function &get_series($uid,calendar_bo $bo=null, $expand=false, $user=null, $master=null)
+	private static function &get_series($uid,calendar_bo $bo=null, $expand=false, $user=null, $master=null, $date_format='server')
 	{
 		if (is_null($bo)) $bo = new calendar_boupdate();
 
@@ -880,7 +887,7 @@ class calendar_groupdav extends Api\CalDAV\Handler
 			'query' => array('cal_uid' => $uid),
 			'filter' => 'owner',  // return all possible entries
 			'daywise' => false,
-			'date_format' => 'server',
+			'date_format' => $date_format,
 			'cfs' => array(),	// read cfs as we use them to store X- attributes
 		);
 		if (is_array($expand)) $params += $expand;
@@ -891,7 +898,7 @@ class calendar_groupdav extends Api\CalDAV\Handler
 			return $events;
 		}
 
-		// find master, which is not always first event, eg. when first event is an exception
+		// find master, which is not always first event, e.g. when first event is an exception
 		$exceptions = array();
 		foreach($events as $k => &$recurrence)
 		{
@@ -904,7 +911,7 @@ class calendar_groupdav extends Api\CalDAV\Handler
 			}
 		}
 		// if recurring event starts in future behind horizont, nothing will be returned by bo::search()
-		if (!isset($master)) $master = $bo->read($uid);
+		if (!isset($master)) $master = $bo->read($uid, null, false, $date_format);
 
 		foreach($events as $k => &$recurrence)
 		{
@@ -912,7 +919,7 @@ class calendar_groupdav extends Api\CalDAV\Handler
 			if ($master && $recurrence['reference'] && $recurrence['reference'] != $master['id'])
 			{
 				unset($events[$k]);
-				continue;	// same uid, but references a different event or is own master
+				continue;	// same uid, but references a different event or its own master
 			}
 			if (!$master || $recurrence['id'] != $master['id'])	// real exception
 			{
@@ -929,7 +936,7 @@ class calendar_groupdav extends Api\CalDAV\Handler
 					$recurrence['participants'][$user] = 'R';
 				}
 				//error_log('real exception: '.array2string($recurrence));
-				// remove from masters recur_exception, as exception is include
+				// remove from masters recur_exception, as exception is included
 				// at least Lightning "understands" EXDATE as exception from what's included
 				// in the whole resource / VCALENDAR component
 				// not removing it causes Lightning to remove the exception itself
@@ -1620,12 +1627,13 @@ class calendar_groupdav extends Api\CalDAV\Handler
 	{
 		if (strpos($column=self::$path_attr,'_') === false) $column = 'cal_'.$column;
 
-		$event = $this->bo->read(array($column => $id, 'cal_deleted IS NULL', 'cal_reference=0'), null, true, 'server');
+		$event = $this->bo->read(array($column => $id, 'cal_deleted IS NULL', 'cal_reference=0'), null, true,
+			$date_format = Api\CalDAV::isJSON() ? 'object' : 'server');
 		if ($event) $event = array_shift($event);	// read with array as 1. param, returns an array of events!
 
 		if (!($retval = $this->bo->check_perms(calendar_bo::ACL_FREEBUSY,$event, 0, 'server')) &&
 			// above can be true, if current user is not in master but just a recurrence
-			(!$event['recur_type'] || !($events = self::get_series($event['uid'], $this->bo))))
+			(!$event['recur_type'] || !($events = self::get_series($event['uid'], $this->bo, false, null, null, $date_format))))
 		{
 			if ($this->debug > 0) error_log(__METHOD__."($id) no READ or FREEBUSY rights returning ".array2string($retval));
 			return $retval;
diff --git a/calendar/inc/class.calendar_rrule.inc.php b/calendar/inc/class.calendar_rrule.inc.php
index e28f6ace1e..01a03ef10d 100644
--- a/calendar/inc/class.calendar_rrule.inc.php
+++ b/calendar/inc/class.calendar_rrule.inc.php
@@ -538,9 +538,9 @@ class calendar_rrule implements Iterator
 			$previous = clone $this->current;
 			$this->next_no_exception();
 		}
-		// if enddate is now before next acurrence, but not on same day, we use previous recurrence
+		// if enddate is now before next occurrence, but not on same day, we use previous recurrence
 		// this can happen if client gives an enddate which is NOT a recurrence date
-		// eg. for a on Monday recurring weekly event a Tuesday as enddate
+		// e.g. for an on Monday recurring weekly event a Tuesday as enddate
 		if ($this->enddate < $this->current  && $this->current->format('Ymd') != $this->enddate->format('Ymd'))
 		{
 			$last = $previous;
diff --git a/doc/REST-CalDAV-CardDAV/Addressbook.md b/doc/REST-CalDAV-CardDAV/Addressbook.md
new file mode 100644
index 0000000000..6fd8935f7e
--- /dev/null
+++ b/doc/REST-CalDAV-CardDAV/Addressbook.md
@@ -0,0 +1,504 @@
+# EGroupware REST API for Addressbook
+
+Authentication is via Basic Auth with username and a password, or a token valid for:
+- either just the given user or all users
+- CalDAV/CardDAV Sync (REST API)
+- Calendar application
+
+Following RFCs / drafts used/planned for JSON encoding of resources
+* [draft-ietf-jmap-jscontact: JSContact: A JSON Representation of Contact Data](https://datatracker.ietf.org/doc/html/draft-ietf-jmap-jscontact) 
+([* see at end of document](#implemented-changes-from-jscontact-draft-08))
+* [draft-ietf-jmap-jscontact-vcard: JSContact: Converting from and to vCard](https://datatracker.ietf.org/doc/html/draft-ietf-jmap-jscontact-vcard/)
+* [rfc8984: JSCalendar: A JSON Representation of Calendar Data](https://datatracker.ietf.org/doc/html/rfc8984)
+
+### Supported request methods and examples
+
+* **GET** to collections with an ```Accept: application/json``` header return all resources (similar to WebDAV PROPFIND)
+<details>
+  <summary>Example: Getting all entries of a given users addessbook</summary>
+  
+```
+curl https://example.org/egroupware/groupdav.php/<username>/addressbook/ -H "Accept: application/pretty+json" --user <username>
+{
+  "responses": {
+    "/<username>/addressbook/1833": {
+      "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
+      "prodId": "EGroupware Addressbook 21.1.001",
+      "created": "2010-10-21T09:55:42Z",
+      "updated": "2014-06-02T14:45:24Z",
+      "name": [
+        { "@type": "NameComponent", "type": "personal", "value": "Default" },
+        { "@type": "NameComponent", "type": "surname", "value": "Tester" }
+      ],
+      "fullName": { "value": "Default Tester" },
+      "organizations": {
+        "org": {
+          "@type": "Organization", 
+          "name": "default.org",
+          "units": {
+            "org_unit": "department.default.org"
+          }
+        }
+      },
+      "emails": {
+        "work": { "@type": "EmailAddress", "email": "test@test.com", "contexts": { "work": true }, "pref": 1 }
+      },
+      "phones": {
+        "tel_work": { "@type": "Phone", "phone": "+49 123 4567890", "pref": 1, "features": { "voice": true }, "contexts": { "work": true } },
+        "tel_cell": { "@type": "Phone", "phone": "012 3723567", "features": { "cell": true }, "contexts": { "work": true } }
+      },
+      "online": {
+        "url": { "@type": "Resource", "resource": "https://www.test.com/", "type": "uri", "contexts": { "work": true } }
+      },
+      "notes": [
+        "Test test TEST\n\\server\\share\n\\\nother\nblah"
+      ],
+    },
+    "/<username>/addressbook/list-36": {
+      "uid": "urn:uuid:dfa5cac5-987b-448b-85d7-6c8b529a835c",
+      "name": "Example distribution list",
+      "card": {
+        "uid": "urn:uuid:dfa5cac5-987b-448b-85d7-6c8b529a835c",
+        "prodId": "EGroupware Addressbook 21.1.001",
+        "updated": "2018-04-11T14:46:43Z",
+        "fullName": { "value": "Example distribution list" }
+      },
+      "members": {
+        "5638-8623c4830472a8ede9f9f8b30d435ea4": true
+      }
+    }
+  }
+}
+```
+</details>
+       
+  following GET parameters are supported to customize the returned properties:
+  - props[]=<DAV-prop-name> eg. props[]=getetag to return only the ETAG (multiple DAV properties can be specified)
+    Default for addressbook collections is to only return address-data (JsContact), other collections return all props.
+  - sync-token=<token> to only request change since last sync-token, like rfc6578 sync-collection REPORT
+  - nresults=N limit number of responses (only for sync-collection / given sync-token parameter!)
+    this will return a "more-results"=true attribute and a new "sync-token" attribute to query for the next chunk
+
+<details>
+   <summary>Example: Getting just ETAGs and displayname of all contacts in a given AB</summary>
+   
+```
+curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/?props[]=getetag&props[]=displayname' -H "Accept: application/pretty+json" --user <username>
+{
+  "responses": {
+    "/addressbook/1833": {
+      "displayname": "Default Tester",
+      "getetag": "\"1833:24\""
+    },
+    "/addressbook/1838": {
+      "displayname": "Test Tester",
+      "getetag": "\"1838:19\""
+    }
+  }
+}
+```
+</details>
+
+<details>
+   <summary>Example: Start using a sync-token to get only changed entries since last sync</summary>
+   
+#### Initial request with empty sync-token and only requesting 10 entries per chunk:
+```
+curl 'https://example.org/egroupware/groupdav.php/addressbook/?sync-token=&nresults=10&props[]=displayname' -H "Accept: application/pretty+json" --user <username>
+{
+  "responses": {
+    "/addressbook/2050": "Frau Margot Test-Notifikation",
+    "/addressbook/2384": "Test Tester",
+    "/addressbook/5462": "Margot Testgedöns",
+    "/addressbook/2380": "Frau Test Defaulterin",
+    "/addressbook/5474": "Noch ein Neuer",
+    "/addressbook/5575": "Mr New Name",
+    "/addressbook/5461": "Herr Hugo Kurt Müller Senior",
+    "/addressbook/5601": "Steve Jobs",
+    "/addressbook/5603": "Ralf Becker",
+    "/addressbook/1838": "Test Tester"
+  },
+  "more-results": true,
+  "sync-token": "https://example.org/egroupware/groupdav.php/addressbook/1400867824"
+}
+```
+#### Requesting next chunk:
+```
+curl 'https://example.org/egroupware/groupdav.php/addressbook/?sync-token=https://example.org/egroupware/groupdav.php/addressbook/1400867824&nresults=10&props[]=displayname' -H "Accept: application/pretty+json" --user <username>
+{
+  "responses": {
+    "/addressbook/1833": "Default Tester",
+    "/addressbook/5597": "Neuer Testschnuffi",
+    "/addressbook/5593": "Muster Max",
+    "/addressbook/5628": "2. Test Contact",
+    "/addressbook/5629": "Testen Tester",
+    "/addressbook/5630": "Testen Tester",
+    "/addressbook/5633": "Testen Tester",
+    "/addressbook/5635": "Test4 Tester",
+    "/addressbook/5638": "Test Kontakt",
+    "/addressbook/5636": "Test Default"
+  },
+  "more-results": true,
+  "sync-token": "https://example.org/egroupware/groupdav.php/addressbook/1427103057"
+}
+```
+</details>
+
+<details>
+   <summary>Example: Requesting only changes since last sync</summary>
+   
+#### ```sync-token``` from last sync need to be specified (note the null for a deleted resource!)
+```
+curl 'https://example.org/egroupware/groupdav.php/addressbook/?sync-token=https://example.org/egroupware/groupdav.php/addressbook/1400867824' -H "Accept: application/pretty+json" --user <username>
+{
+  "responses": {
+    "/addressbook/5597": null,
+    "/addressbook/5593": {
+      "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
+      "prodId": "EGroupware Addressbook 21.1.001",
+      "created": "2010-10-21T09:55:42Z",
+      "updated": "2014-06-02T14:45:24Z",
+      "name": [
+        { "@type": "NameComponent", "type": "personal", "value": "Default" },
+        { "@type": "NameComponent", "type": "surname", "value": "Tester" }
+      ],
+      "fullName": "Default Tester",
+....
+    }
+  },
+  "sync-token": "https://example.org/egroupware/groupdav.php/addressbook/1427103057"
+}
+```
+</details>
+
+* **GET**  requests with an ```Accept: application/json``` header can be used to retrieve single resources / JsContact or JsCalendar schema
+<details>
+   <summary>Example: GET request for a single resource showcasing available fieldes</summary>
+   
+```
+curl 'https://example.org/egroupware/groupdav.php/addressbook/6502' -H "Accept: application/pretty+json" --user <username>
+{
+    "uid": "addressbook-6502-8623c4830472a8ede9f9f8b30d435ea4",
+    "prodId": "EGroupware Addressbook 21.1.003",
+    "created": "2022-12-14T13:35:02Z",
+    "updated": "2022-12-14T13:39:14Z",
+    "kind": "individual",
+    "name": [
+        { "@type": "NameComponent", "type": "prefix", "value": "Prefix/Title" },
+        { "@type": "NameComponent", "type": "personal", "value": "Frist" },
+        { "@type": "NameComponent", "type": "additional", "value": "Middle" },
+        { "@type": "NameComponent", "type": "surname", "value": "Last" },
+        { "@type": "NameComponent", "type": "suffix", "value": "Postfix" }
+    ],
+    "fullName": "Prefix/Title Frist Middle Last Postfix",
+    "organizations": {
+        "org": {
+            "@type": "Organization",
+            "name": "Organisation",
+            "units": { "org_unit": "Department" }
+        }
+    },
+    "titles": {
+        "title": {
+            "@type": "Title",
+            "title": "Postion",
+            "organization": "org"
+        },
+        "role": {
+            "@type": "Title",
+            "title": "Occupation",
+            "organization": "org"
+        }
+    },
+    "emails": {
+        "work": {
+            "@type": "EmailAddress",
+            "email": "email@example.org",
+            "contexts": { "work": true },
+            "pref": 1
+        },
+        "private": {
+            "@type": "EmailAddress",
+            "email": "private.email@example.org",
+            "contexts": { "private": true }
+        }
+    },
+    "phones": {
+        "tel_work": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "voice": true },
+            "contexts": { "work": true }
+        },
+        "tel_cell": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "cell": true },
+            "contexts": { "work": true }
+        },
+        "tel_fax": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "fax": true },
+            "contexts": { "work": true }
+        },
+        "tel_assistent": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "voice": true },
+            "contexts": { "assistant": true }
+        },
+        "tel_car": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "voice": true },
+            "contexts": { "car": true }
+        },
+        "tel_pager": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "pager": true },
+            "contexts": { "work": true }
+        },
+        "tel_home": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "voice": true },
+            "contexts": { "private": true }
+        },
+        "tel_fax_home": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "fax": true },
+            "contexts": { "private": true }
+        },
+        "tel_cell_private": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "cell": true },
+            "contexts": { "private": true }
+        },
+        "tel_other": {
+            "@type": "Phone",
+            "phone": "+1(234)5678901",
+            "features": { "voice": true },
+            "contexts": { "work": true }
+        }
+    },
+    "online": {
+        "url": {
+            "@type": "Resource",
+            "resource": "https://example.org",
+            "type": "uri",
+            "contexts": { "work": true }
+        },
+        "url_home": {
+            "@type": "Resource",
+            "resource": "https://private.example.org",
+            "type": "uri",
+            "contexts": { "private": true }
+        }
+    },
+    "addresses": {
+        "work": {
+            "@type": "Address",
+            "locality": "City",
+            "region": "Rheinland-Pfalz",
+            "country": "DEUTSCHLAND",
+            "postcode": "12345",
+            "countryCode": "DE",
+            "street": [
+                { "@type": "StreetComponent", "type": "name", "value": "Street" },
+                { "@type": "StreetComponent", "type": "separator", "value": "\n" },
+                { "@type": "StreetComponent", "type": "name", "value": "Street2" ],
+            "contexts": { "work": true },
+            "pref": 1
+        },
+        "home": {
+            "@type": "Address",
+            "locality": "PrivateCity",
+            "country": "DEUTSCHLAND",
+            "postcode": "12345",
+            "countryCode": "DE",
+            "street": [
+                { "@type": "StreetComponent", "type": "name", "value": "PrivateStreet" },
+                { "@type": "StreetComponent", "type": "separator", "value": "\n" },
+                { "@type": "StreetComponent", "type": "name", "value": "PrivateStreet2" }
+            ],
+            "contexts": { "home": true }
+        }
+    },
+    "photos": {
+        "photo": {
+            "@type": "File",
+            "href": "https://boulder.egroupware.org/egroupware/api/avatar.php?contact_id=6502&lavatar=1&etag=0",
+            "mediaType": "image/jpeg"
+        }
+    },
+    "anniversaries": {
+        "bday": {
+            "@type": "Anniversary",
+            "type": "birth",
+            "date": "2022-12-14"
+        }
+    },
+    "categories": {
+        "Kategorie": true,
+        "My Contacts": true
+    },
+    "egroupware.org:assistant": "Assistent"
+}
+```
+</details>
+
+* **POST** requests to collection with a ```Content-Type: application/json``` header add new entries in addressbook or calendar collections
+       (Location header in response gives URL of new resource)
+<details>
+   <summary>Example: POST request to create a new resource</summary>
+   
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/' -X POST -d @- -H "Content-Type: application/json" --user <username>
+{
+  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
+  "prodId": "EGroupware Addressbook 21.1.001",
+  "created": "2010-10-21T09:55:42Z",
+  "updated": "2014-06-02T14:45:24Z",
+  "name": [
+    { "type": "@type": "NameComponent", "personal", "value": "Default" },
+    { "type": "@type": "NameComponent", "surname", "value": "Tester" }
+  ],
+  "fullName": { "value": "Default Tester" },
+....
+}
+EOF
+
+HTTP/1.1 201 Created
+Location: https://example.org/egroupware/groupdav.php/<username>/addressbook/1234
+```
+</details>
+
+<details>
+   <summary>Example: POST request to create a new resource using flat attributes (JSON patch syntax) eg. for a simple Wordpress contact-form</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/' -X POST -d @- -H "Content-Type: application/json" --user <username>
+{
+  "fullName": "First Tester",
+  "name/personal": "First",
+  "name/surname":  "Tester",
+  "organizations/org/name": "Test Organization",
+  "emails/work": "test.user@test-user.org",
+  "addresses/work/locality": "Test-Town",
+  "addresses/work/postcode": "12345",
+  "addresses/work/street": "Teststr. 123",
+  "addresses/work/country": "Germany",
+  "addresses/work/countryCode": "DE",
+  "phones/tel_work": "+49 123 4567890",
+  "online/url": "https://www.example.org/",
+  "notes/note": "This is a note.",
+  "egroupware.org:customfields/Test": "Content for Test"
+}
+EOF
+
+HTTP/1.1 201 Created
+Location: https://example.org/egroupware/groupdav.php/<username>/addressbook/1234
+```
+</details>
+
+* **PUT**  requests with  a ```Content-Type: application/json``` header allow modifying single resources (requires to specify all attributes!)
+
+<details>
+   <summary>Example: PUT request to update a resource</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/1234' -X PUT -d @- -H "Content-Type: application/json" --user <username>
+{
+  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
+  "prodId": "EGroupware Addressbook 21.1.001",
+  "created": "2010-10-21T09:55:42Z",
+  "updated": "2014-06-02T14:45:24Z",
+  "name": [
+    { "type": "@type": "NameComponent", "personal", "value": "Default" },
+    { "type": "@type": "NameComponent", "surname", "value": "Tester" }
+  ],
+  "fullName": { "value": "Default Tester" },
+....
+}
+EOF
+
+HTTP/1.1 204 No Content
+```
+</details>
+
+<details>
+   <summary>Example: PUT request with UID to update an existing resource or create it, if not exists</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/5638-8623c4830472a8ede9f9f8b30d435ea4' -X PUT -d @- -H "Content-Type: application/json" --user <username>
+{
+  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
+  "prodId": "EGroupware Addressbook 21.1.001",
+  "created": "2010-10-21T09:55:42Z",
+  "updated": "2014-06-02T14:45:24Z",
+  "name": [
+    { "type": "@type": "NameComponent", "personal", "value": "Default" },
+    { "type": "@type": "NameComponent", "surname", "value": "Tester" }
+  ],
+  "fullName": { "value": "Default Tester" },
+....
+}
+EOF
+```
+Update of an existing one:
+```
+HTTP/1.1 204 No Content
+```
+New contact:
+```
+HTTP/1.1 201 Created
+Location: https://example.org/egroupware/groupdav.php/<username>/addressbook/1234
+```
+</details>
+
+
+* **PATCH** request with a ```Content-Type: application/json``` header allow to modify a single resource by only specifying changed attributes as a [PatchObject](https://www.rfc-editor.org/rfc/rfc8984.html#type-PatchObject)
+
+<details>
+   <summary>Example: PATCH request to modify a contact with partial data</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/1234' -X PATCH -d @- -H "Content-Type: application/json" --user <username>
+{
+  "name": [
+    {
+      "@type": "NameComponent",
+      "type": "personal",
+      "value": "Testfirst"
+    },
+    {
+      "@type": "NameComponent",
+      "type": "surname",
+      "value": "Username"
+    }
+  ],
+  "fullName": "Testfirst Username",
+  "organizations/org/name": "Test-User.org",
+  "emails/work/email": "test.user@test-user.org"
+}
+EOF
+
+HTTP/1.1 204 No content
+```
+</details>
+
+* **DELETE** requests delete single resources
+
+* one can use ```Accept: application/pretty+json``` to receive pretty-printed JSON eg. for debugging and exploring the API
+
+#### Implemented [changes from JsContact draft 08](https://github.com/rsto/draft-stepanek-jscontact/compare/draft-ietf-jmap-jscontact-08):
+* localizedString type / object is removed in favor or regular String type and a [localizations object like in JsCalendar](https://datatracker.ietf.org/doc/html/rfc8984#section-4.6.1)
+* [Vendor-specific Property Extensions and Values](https://datatracker.ietf.org/doc/html/draft-ietf-jmap-jscontact-07#section-1.3) 
+use ```<domain-name>:<name>``` like in JsCalendar
+* top-level objects need a ```@type``` attribute with one of the following values: 
+```NameComponent```, ```Organization```, ```Title```, ```Phone```, ```Resource```, ```File```, ```ContactLanguage```, 
+```Address```, ```StreetComponent```, ```Anniversary```, ```PersonalInformation```
\ No newline at end of file
diff --git a/doc/REST-CalDAV-CardDAV/Calendar.md b/doc/REST-CalDAV-CardDAV/Calendar.md
new file mode 100644
index 0000000000..53e64f3e23
--- /dev/null
+++ b/doc/REST-CalDAV-CardDAV/Calendar.md
@@ -0,0 +1,383 @@
+# EGroupware REST API for Calendar
+
+Authentication is via Basic Auth with username and a password, or a token valid for:
+- either just the given user or all users
+- CalDAV/CardDAV Sync (REST API)
+- Calendar application
+
+Following RFCs / drafts used/planned for JSON encoding of resources
+* [rfc8984: JSCalendar: A JSON Representation of Calendar Data](https://datatracker.ietf.org/doc/html/rfc8984)
+
+### Supported request methods and examples
+
+* **GET** to collections with an ```Accept: application/json``` header return all resources (similar to WebDAV PROPFIND)
+<details>
+  <summary>Example: Getting all entries of a given users calendar</summary>
+
+```
+curl https://example.org/egroupware/groupdav.php/<username>/calendar/ -H "Accept: application/pretty+json" --user <username>
+{
+  "responses": {
+    "/<username>/calendar/5695": {
+        "@type": "Event",
+        "prodId": "EGroupware Calendar 23.1.002",
+        "uid": "calendar-5695-34b52fc11cfa7e9acea5732210a53f48",
+        "sequence": "1",
+        "created": "2023-07-14T06:05:53Z",
+        "updated": "2023-07-14T08:00:04Z",
+        "title": "Test",
+        "start": "2023-07-14T10:00:00",
+        "timeZone": "Europe/Berlin",
+        "duration": "PT1H",
+        "participants": {
+            "5": {
+                "@type": "Participant",
+                "name": "Ralf Becker",
+                "email": "ralf@boulder.egroupware.org",
+                "kind": "individual",
+                "roles": {
+                    "owner": true,
+                    "chair": true
+                },
+                "participationStatus": "accepted"
+            }
+        },
+        "status": "confirmed",
+        "priority": 5,
+        "privacy": "public"
+    },
+    "/<username>/calendar/5699": {
+        "@type": "Event",
+        "prodId": "EGroupware Calendar 23.1.002",
+        "uid": "calendar-5699-34b52fc11cfa7e9acea5732210a53f48",
+        "sequence": "5",
+        "created": "2023-07-24T10:06:23Z",
+        "updated": "2023-07-24T13:11:49Z",
+        "title": "Monday and Wednesday 13h",
+        "start": "2023-07-24T13:00:00",
+        "timeZone": "Europe/Berlin",
+        "duration": "PT1H",
+        "recurrenceRules": [
+            {
+                "@type": "RecurrenceRule",
+                "frequency": "weekly",
+                "until": "2023-08-30T13:00:00",
+                "byDay": {
+                    "@type": "NDay",
+                    "day": "mo,we"
+                }
+            }
+        ],
+        "recurrenceOverrides": {
+            "2023-07-31T13:00:00": { "excluded": true },
+            "2023-07-26T13:00:00": {
+                "sequence": "1",
+                "updated": "2023-07-24T11:39:44Z",
+                "title": "Monday und Wednesday 13h, but 26th 14h",
+                "start": "2023-07-26T14:00:00",
+                "description": "sdfasdf",
+                "showWithoutTime": null,
+                "categories": null,
+                "alerts": {
+                    "64be4dc0-a044-4b27-b450-0026ac120002": {
+                        "@type": "Alert",
+                        "trigger": {
+                            "@type": "OffsetTrigger",
+                            "offset": 0
+                        }
+                    },
+                    "64be4d1f-c958-4fbd-afc3-0026ac120002": null
+                }
+            }
+        },
+        "participants": {
+            "5": {
+                "@type": "Participant",
+                "name": "Ralf Becker",
+                "email": "ralf@boulder.egroupware.org",
+                "kind": "individual",
+                "roles": {
+                    "owner": true,
+                    "chair": true
+                },
+                "participationStatus": "accepted"
+            }
+        },
+        "alerts": {
+            "64be4d1f-c958-4fbd-afc3-0026ac120002": {
+                "@type": "Alert",
+                "trigger": {
+                    "@type": "OffsetTrigger",
+                    "offset": 0
+                }
+            }
+        },
+        "status": "confirmed",
+        "priority": 5,
+        "privacy": "public"
+    },
+    "/<username>/calendar/5701": {
+        "@type": "Event",
+        "prodId": "EGroupware Calendar 23.1.002",
+        "uid": "calendar-5701-34b52fc11cfa7e9acea5732210a53f48",
+        "sequence": "1",
+        "created": "2023-07-24T12:31:58Z",
+        "updated": "2023-07-24T12:41:54Z",
+        "title": "Di und Do den ganzen Tag",
+        "start": "2023-07-25T00:00:00",
+        "timeZone": "Europe/Berlin",
+        "showWithoutTime": true,
+        "duration": "P1D",
+        "recurrenceRules": [
+            {
+                "@type": "RecurrenceRule",
+                "frequency": "weekly",
+                "until": "2023-08-03T00:00:00",
+                "byDay": {
+                    "@type": "NDay",
+                    "day": "tu,th"
+                }
+            }
+        ],
+        "recurrenceOverrides": {
+            "2023-07-27T00:00:00": {
+                "title": "Di und Do den ganzen Tag: AUSNAHME",
+                "start": "2023-07-27T00:00:00",
+                "description": "adsfads",
+                "sequence": null,
+                "categories": null,
+                "participants": {
+                    "44": {
+                        "@type": "Participant",
+                        "name": "Birgit Becker",
+                        "email": "birgit@boulder.egroupware.org",
+                        "kind": "individual",
+                        "roles": { "attendee": true },
+                        "participationStatus": "needs-action"
+                    }
+                },
+                "alerts": {
+                    "64be7192-d4e4-4609-8c7a-004dac120002": {
+                        "@type": "Alert",
+                        "trigger": {
+                            "@type": "OffsetTrigger",
+                            "offset": 0
+                        }
+                    },
+                    "64be6f3e-bc8c-4e78-9f96-004bac120002": null
+                }
+            }
+        },
+        "freeBusyStatus": "free",
+        "participants": {
+            "5": {
+                "@type": "Participant",
+                "name": "Ralf Becker",
+                "email": "ralf@boulder.egroupware.org",
+                "kind": "individual",
+                "roles": {
+                    "owner": true,
+                    "chair": true
+                },
+                "participationStatus": "accepted"
+            }
+        },
+        "alerts": {
+            "64be6f3e-bc8c-4e78-9f96-004bac120002": {
+                "@type": "Alert",
+                "trigger": {
+                    "@type": "OffsetTrigger",
+                    "offset": 0
+                }
+            }
+        },
+        "status": "confirmed",
+        "priority": 5,
+        "privacy": "public"
+    }
+  }
+}
+```
+</details>
+
+following GET parameters are supported to customize the returned properties:
+- props[]=<DAV-prop-name> eg. props[]=getetag to return only the ETAG (multiple DAV properties can be specified)
+  Default for addressbook collections is to only return address-data (JsContact), other collections return all props.
+- sync-token=<token> to only request change since last sync-token, like rfc6578 sync-collection REPORT
+- nresults=N limit number of responses (only for sync-collection / given sync-token parameter!)
+  this will return a "more-results"=true attribute and a new "sync-token" attribute to query for the next chunk
+
+Examples: see addressbook
+
+
+* **GET**  requests with an ```Accept: application/json``` header can be used to retrieve single resources / JsContact or JsCalendar schema
+<details>
+   <summary>Example: GET request for a single resource</summary>
+
+```
+curl 'https://example.org/egroupware/groupdav.php/addressbook/6502' -H "Accept: application/pretty+json" --user <username>
+{
+    "@type": "Event",
+    "prodId": "EGroupware Calendar 23.1.002",
+    "uid": "calendar-5695-34b52fc11cfa7e9acea5732210a53f48",
+    "sequence": "1",
+    "created": "2023-07-14T06:05:53Z",
+    "updated": "2023-07-14T08:00:04Z",
+    "title": "Test",
+    "start": "2023-07-14T10:00:00",
+    "timeZone": "Europe/Berlin",
+    "duration": "PT1H",
+    "participants": {
+        "5": {
+            "@type": "Participant",
+            "name": "Ralf Becker",
+            "email": "ralf@boulder.egroupware.org",
+            "kind": "individual",
+            "roles": {
+                "owner": true,
+                "chair": true
+            },
+            "participationStatus": "accepted"
+        }
+    },
+    "status": "confirmed",
+    "priority": 5,
+    "privacy": "public"
+}
+```
+</details>
+
+* **POST** requests to collection with a ```Content-Type: application/json``` header add new entries in addressbook or calendar collections
+  (Location header in response gives URL of new resource)
+<details>
+   <summary>Example: POST request to create a new resource and use "Prefer: return=representation" to get it fully expanded back</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/calendar/' -X POST -d @- -H "Content-Type: application/json" -H "Prefer: return=representation" --user <username>
+{                      
+  "title": "Test 25th",
+  "start": "2023-07-25T10:00:00",
+  "timeZone": "Europe/Berlin",
+  "duration": "PT1H" 
+}
+EOF
+
+HTTP/1.1 201 Created
+Content-Type: application/jscalendar+json;type=event;charset=utf-8
+Location: /egroupware/groupdav.php/ralf/calendar/5704
+ETag: "5704:0:1690209221"
+Schedule-Tag: "5704:0"
+X-WebDAV-Status: 201 Created
+
+{
+  "@type":"Event",
+  "prodId":"EGroupware Calendar 23.1.002",
+  "uid":"urn:uuid:e2b7278b-d91a-47d1-85ee-19dd1fb9b315",
+  "created":"2023-07-24T14:33:41Z",
+  "updated":"2023-07-24T14:33:41Z",
+  "title":"Test 25th",
+  "start":"2023-07-25T10:00:00",
+  "timeZone":"Europe/Berlin",
+  "duration":"PT1H",
+  "participants":{
+    "5":{
+      "@type":"Participant",
+      "name":"Ralf Becker",
+      "email":"ralf@boulder.egroupware.org",
+      "kind":"individual",
+      "roles":{
+        "owner":true,
+        "chair":true
+      },
+      "participationStatus":"accepted"
+    }
+  }
+  "status":"confirmed",
+  "priority":5,
+  "privacy":"public"
+}
+```
+</details>
+
+
+* **PUT**  requests with  a ```Content-Type: application/json``` header allow modifying single resources (requires to specify all attributes!)
+
+<details>
+   <summary>Example: PUT request to update a resource</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/1234' -X PUT -d @- -H "Content-Type: application/json" --user <username>
+{
+  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
+  "prodId": "EGroupware Addressbook 21.1.001",
+  "created": "2010-10-21T09:55:42Z",
+  "updated": "2014-06-02T14:45:24Z",
+  "name": [
+    { "type": "@type": "NameComponent", "personal", "value": "Default" },
+    { "type": "@type": "NameComponent", "surname", "value": "Tester" }
+  ],
+  "fullName": { "value": "Default Tester" },
+....
+}
+EOF
+
+HTTP/1.1 204 No Content
+```
+</details>
+
+<details>
+   <summary>Example: PUT request with UID to update an existing resource or create it, if not exists</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/calendar/5638-8623c4830472a8ede9f9f8b30d435ea4' -X PUT -d @- -H "Content-Type: application/json" --user <username>
+{
+  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
+  "title": "Testevent",
+  "start": "2023-07-24T12:00:00",
+  "timeZone": "Europe/Berlin",
+  "duration": "PT2H",
+....
+}
+EOF
+```
+Update of an existing one:
+```
+HTTP/1.1 204 No Content
+```
+New contact:
+```
+HTTP/1.1 201 Created
+Location: https://example.org/egroupware/groupdav.php/<username>/calendar/1234
+```
+</details>
+
+
+* **PATCH** request with a ```Content-Type: application/json``` header allow to modify a single resource by only specifying changed attributes as a [PatchObject](https://www.rfc-editor.org/rfc/rfc8984.html#type-PatchObject)
+
+<details>
+   <summary>Example: PATCH request to modify an event with partial data</summary>
+
+```
+cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/calendar/1234' -X PATCH -d @- -H "Content-Type: application/json" --user <username>
+{
+  "title": "New title"
+}
+EOF
+
+HTTP/1.1 204 No content
+```
+</details>
+
+* **DELETE** requests delete single resources
+<details>
+   <summary>Example: Delete an existing event</summary>
+> Please note: the "Accept: application/json" header is required, as the CalDAV server would return 404 NotFound as the url does NOT end with .ics
+
+```
+curl -i 'https://example.org/egroupware/groupdav.php/<username>/calendar/1234' -X DELETE -H "Accept: application/json" --user <username>
+
+HTTP/1.1 204 No Content
+```
+</details>
+
+* one can use ```Accept: application/pretty+json``` to receive pretty-printed JSON e.g. for debugging and exploring the API
\ No newline at end of file
diff --git a/doc/REST-CalDAV-CardDAV/README.md b/doc/REST-CalDAV-CardDAV/README.md
index 2e78d59446..cc6824d718 100644
--- a/doc/REST-CalDAV-CardDAV/README.md
+++ b/doc/REST-CalDAV-CardDAV/README.md
@@ -36,513 +36,26 @@ One can use the following URLs relative (!) to https://example.org/egroupware/gr
 Shared addressbooks or calendars are only shown in the users home-set, if he subscribed to it via his CalDAV preferences!
 
 Calling one of the above collections with a GET request / regular browser generates an automatic index
-from the data of an allprop PROPFIND, allow browsing CalDAV/CardDAV tree with a regular browser.
+from the data of an ```allprop``` PROPFIND, allow browsing CalDAV/CardDAV tree with a regular browser.
 
 ## REST API: using EGroupware CalDAV/CardDAV server with JSON
-> currently implemented only for contacts and calendar (without recurring events)!
+- [Addressbook](Addressbook.md)
+- [Calendar](Calendar.md) (currently recurring events are readonly, they are returned but can not be created or modified)
+- [Mail](Mail.md) (currently only sending mails or opening interactive compose windows)
 
-Following RFCs / drafts used/planned for JSON encoding of ressources
+Following RFCs / drafts used/planned for JSON encoding of resources
 * [draft-ietf-jmap-jscontact: JSContact: A JSON Representation of Contact Data](https://datatracker.ietf.org/doc/html/draft-ietf-jmap-jscontact) 
 ([* see at end of document](#implemented-changes-from-jscontact-draft-08))
 * [draft-ietf-jmap-jscontact-vcard: JSContact: Converting from and to vCard](https://datatracker.ietf.org/doc/html/draft-ietf-jmap-jscontact-vcard/)
 * [rfc8984: JSCalendar: A JSON Representation of Calendar Data](https://datatracker.ietf.org/doc/html/rfc8984)
 
-### Supported request methods and examples
-
-* **GET** to collections with an ```Accept: application/json``` header return all resources (similar to WebDAV PROPFIND)
-<details>
-  <summary>Example: Getting all entries of a given users addessbook</summary>
-  
-```
-curl https://example.org/egroupware/groupdav.php/<username>/addressbook/ -H "Accept: application/pretty+json" --user <username>
-{
-  "responses": {
-    "/<username>/addressbook/1833": {
-      "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
-      "prodId": "EGroupware Addressbook 21.1.001",
-      "created": "2010-10-21T09:55:42Z",
-      "updated": "2014-06-02T14:45:24Z",
-      "name": [
-        { "@type": "NameComponent", "type": "personal", "value": "Default" },
-        { "@type": "NameComponent", "type": "surname", "value": "Tester" }
-      ],
-      "fullName": { "value": "Default Tester" },
-      "organizations": {
-        "org": {
-          "@type": "Organization", 
-          "name": "default.org",
-          "units": {
-            "org_unit": "department.default.org"
-          }
-        }
-      },
-      "emails": {
-        "work": { "@type": "EmailAddress", "email": "test@test.com", "contexts": { "work": true }, "pref": 1 }
-      },
-      "phones": {
-        "tel_work": { "@type": "Phone", "phone": "+49 123 4567890", "pref": 1, "features": { "voice": true }, "contexts": { "work": true } },
-        "tel_cell": { "@type": "Phone", "phone": "012 3723567", "features": { "cell": true }, "contexts": { "work": true } }
-      },
-      "online": {
-        "url": { "@type": "Resource", "resource": "https://www.test.com/", "type": "uri", "contexts": { "work": true } }
-      },
-      "notes": [
-        "Test test TEST\n\\server\\share\n\\\nother\nblah"
-      ],
-    },
-    "/<username>/addressbook/list-36": {
-      "uid": "urn:uuid:dfa5cac5-987b-448b-85d7-6c8b529a835c",
-      "name": "Example distribution list",
-      "card": {
-        "uid": "urn:uuid:dfa5cac5-987b-448b-85d7-6c8b529a835c",
-        "prodId": "EGroupware Addressbook 21.1.001",
-        "updated": "2018-04-11T14:46:43Z",
-        "fullName": { "value": "Example distribution list" }
-      },
-      "members": {
-        "5638-8623c4830472a8ede9f9f8b30d435ea4": true
-      }
-    }
-  }
-}
-```
-</details>
-       
-  following GET parameters are supported to customize the returned properties:
-  - props[]=<DAV-prop-name> eg. props[]=getetag to return only the ETAG (multiple DAV properties can be specified)
-    Default for addressbook collections is to only return address-data (JsContact), other collections return all props.
-  - sync-token=<token> to only request change since last sync-token, like rfc6578 sync-collection REPORT
-  - nresults=N limit number of responses (only for sync-collection / given sync-token parameter!)
-    this will return a "more-results"=true attribute and a new "sync-token" attribute to query for the next chunk
-
-<details>
-   <summary>Example: Getting just ETAGs and displayname of all contacts in a given AB</summary>
-   
-```
-curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/?props[]=getetag&props[]=displayname' -H "Accept: application/pretty+json" --user <username>
-{
-  "responses": {
-    "/addressbook/1833": {
-      "displayname": "Default Tester",
-      "getetag": "\"1833:24\""
-    },
-    "/addressbook/1838": {
-      "displayname": "Test Tester",
-      "getetag": "\"1838:19\""
-    }
-  }
-}
-```
-</details>
-
-<details>
-   <summary>Example: Start using a sync-token to get only changed entries since last sync</summary>
-   
-#### Initial request with empty sync-token and only requesting 10 entries per chunk:
-```
-curl 'https://example.org/egroupware/groupdav.php/addressbook/?sync-token=&nresults=10&props[]=displayname' -H "Accept: application/pretty+json" --user <username>
-{
-  "responses": {
-    "/addressbook/2050": "Frau Margot Test-Notifikation",
-    "/addressbook/2384": "Test Tester",
-    "/addressbook/5462": "Margot Testgedöns",
-    "/addressbook/2380": "Frau Test Defaulterin",
-    "/addressbook/5474": "Noch ein Neuer",
-    "/addressbook/5575": "Mr New Name",
-    "/addressbook/5461": "Herr Hugo Kurt Müller Senior",
-    "/addressbook/5601": "Steve Jobs",
-    "/addressbook/5603": "Ralf Becker",
-    "/addressbook/1838": "Test Tester"
-  },
-  "more-results": true,
-  "sync-token": "https://example.org/egroupware/groupdav.php/addressbook/1400867824"
-}
-```
-#### Requesting next chunk:
-```
-curl 'https://example.org/egroupware/groupdav.php/addressbook/?sync-token=https://example.org/egroupware/groupdav.php/addressbook/1400867824&nresults=10&props[]=displayname' -H "Accept: application/pretty+json" --user <username>
-{
-  "responses": {
-    "/addressbook/1833": "Default Tester",
-    "/addressbook/5597": "Neuer Testschnuffi",
-    "/addressbook/5593": "Muster Max",
-    "/addressbook/5628": "2. Test Contact",
-    "/addressbook/5629": "Testen Tester",
-    "/addressbook/5630": "Testen Tester",
-    "/addressbook/5633": "Testen Tester",
-    "/addressbook/5635": "Test4 Tester",
-    "/addressbook/5638": "Test Kontakt",
-    "/addressbook/5636": "Test Default"
-  },
-  "more-results": true,
-  "sync-token": "https://example.org/egroupware/groupdav.php/addressbook/1427103057"
-}
-```
-</details>
-
-<details>
-   <summary>Example: Requesting only changes since last sync</summary>
-   
-#### ```sync-token``` from last sync need to be specified (note the null for a deleted resource!)
-```
-curl 'https://example.org/egroupware/groupdav.php/addressbook/?sync-token=https://example.org/egroupware/groupdav.php/addressbook/1400867824' -H "Accept: application/pretty+json" --user <username>
-{
-  "responses": {
-    "/addressbook/5597": null,
-    "/addressbook/5593": {
-      "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
-      "prodId": "EGroupware Addressbook 21.1.001",
-      "created": "2010-10-21T09:55:42Z",
-      "updated": "2014-06-02T14:45:24Z",
-      "name": [
-        { "@type": "NameComponent", "type": "personal", "value": "Default" },
-        { "@type": "NameComponent", "type": "surname", "value": "Tester" }
-      ],
-      "fullName": "Default Tester",
-....
-    }
-  },
-  "sync-token": "https://example.org/egroupware/groupdav.php/addressbook/1427103057"
-}
-```
-</details>
-
-* **GET**  requests with an ```Accept: application/json``` header can be used to retrieve single resources / JsContact or JsCalendar schema
-<details>
-   <summary>Example: GET request for a single resource showcasing available fieldes</summary>
-   
-```
-curl 'https://example.org/egroupware/groupdav.php/addressbook/6502' -H "Accept: application/pretty+json" --user <username>
-{
-    "uid": "addressbook-6502-8623c4830472a8ede9f9f8b30d435ea4",
-    "prodId": "EGroupware Addressbook 21.1.003",
-    "created": "2022-12-14T13:35:02Z",
-    "updated": "2022-12-14T13:39:14Z",
-    "kind": "individual",
-    "name": [
-        { "@type": "NameComponent", "type": "prefix", "value": "Prefix/Title" },
-        { "@type": "NameComponent", "type": "personal", "value": "Frist" },
-        { "@type": "NameComponent", "type": "additional", "value": "Middle" },
-        { "@type": "NameComponent", "type": "surname", "value": "Last" },
-        { "@type": "NameComponent", "type": "suffix", "value": "Postfix" }
-    ],
-    "fullName": "Prefix/Title Frist Middle Last Postfix",
-    "organizations": {
-        "org": {
-            "@type": "Organization",
-            "name": "Organisation",
-            "units": { "org_unit": "Department" }
-        }
-    },
-    "titles": {
-        "title": {
-            "@type": "Title",
-            "title": "Postion",
-            "organization": "org"
-        },
-        "role": {
-            "@type": "Title",
-            "title": "Occupation",
-            "organization": "org"
-        }
-    },
-    "emails": {
-        "work": {
-            "@type": "EmailAddress",
-            "email": "email@example.org",
-            "contexts": { "work": true },
-            "pref": 1
-        },
-        "private": {
-            "@type": "EmailAddress",
-            "email": "private.email@example.org",
-            "contexts": { "private": true }
-        }
-    },
-    "phones": {
-        "tel_work": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "voice": true },
-            "contexts": { "work": true }
-        },
-        "tel_cell": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "cell": true },
-            "contexts": { "work": true }
-        },
-        "tel_fax": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "fax": true },
-            "contexts": { "work": true }
-        },
-        "tel_assistent": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "voice": true },
-            "contexts": { "assistant": true }
-        },
-        "tel_car": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "voice": true },
-            "contexts": { "car": true }
-        },
-        "tel_pager": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "pager": true },
-            "contexts": { "work": true }
-        },
-        "tel_home": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "voice": true },
-            "contexts": { "private": true }
-        },
-        "tel_fax_home": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "fax": true },
-            "contexts": { "private": true }
-        },
-        "tel_cell_private": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "cell": true },
-            "contexts": { "private": true }
-        },
-        "tel_other": {
-            "@type": "Phone",
-            "phone": "+1(234)5678901",
-            "features": { "voice": true },
-            "contexts": { "work": true }
-        }
-    },
-    "online": {
-        "url": {
-            "@type": "Resource",
-            "resource": "https://example.org",
-            "type": "uri",
-            "contexts": { "work": true }
-        },
-        "url_home": {
-            "@type": "Resource",
-            "resource": "https://private.example.org",
-            "type": "uri",
-            "contexts": { "private": true }
-        }
-    },
-    "addresses": {
-        "work": {
-            "@type": "Address",
-            "locality": "City",
-            "region": "Rheinland-Pfalz",
-            "country": "DEUTSCHLAND",
-            "postcode": "12345",
-            "countryCode": "DE",
-            "street": [
-                { "@type": "StreetComponent", "type": "name", "value": "Street" },
-                { "@type": "StreetComponent", "type": "separator", "value": "\n" },
-                { "@type": "StreetComponent", "type": "name", "value": "Street2" ],
-            "contexts": { "work": true },
-            "pref": 1
-        },
-        "home": {
-            "@type": "Address",
-            "locality": "PrivateCity",
-            "country": "DEUTSCHLAND",
-            "postcode": "12345",
-            "countryCode": "DE",
-            "street": [
-                { "@type": "StreetComponent", "type": "name", "value": "PrivateStreet" },
-                { "@type": "StreetComponent", "type": "separator", "value": "\n" },
-                { "@type": "StreetComponent", "type": "name", "value": "PrivateStreet2" }
-            ],
-            "contexts": { "home": true }
-        }
-    },
-    "photos": {
-        "photo": {
-            "@type": "File",
-            "href": "https://boulder.egroupware.org/egroupware/api/avatar.php?contact_id=6502&lavatar=1&etag=0",
-            "mediaType": "image/jpeg"
-        }
-    },
-    "anniversaries": {
-        "bday": {
-            "@type": "Anniversary",
-            "type": "birth",
-            "date": "2022-12-14"
-        }
-    },
-    "categories": {
-        "Kategorie": true,
-        "My Contacts": true
-    },
-    "egroupware.org:assistant": "Assistent"
-}
-```
-</details>
-
-* **POST** requests to collection with a ```Content-Type: application/json``` header add new entries in addressbook or calendar collections
-       (Location header in response gives URL of new resource)
-<details>
-   <summary>Example: POST request to create a new resource</summary>
-   
-```
-cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/' -X POST -d @- -H "Content-Type: application/json" --user <username>
-{
-  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
-  "prodId": "EGroupware Addressbook 21.1.001",
-  "created": "2010-10-21T09:55:42Z",
-  "updated": "2014-06-02T14:45:24Z",
-  "name": [
-    { "type": "@type": "NameComponent", "personal", "value": "Default" },
-    { "type": "@type": "NameComponent", "surname", "value": "Tester" }
-  ],
-  "fullName": { "value": "Default Tester" },
-....
-}
-EOF
-
-HTTP/1.1 201 Created
-Location: https://example.org/egroupware/groupdav.php/<username>/addressbook/1234
-```
-</details>
-
-<details>
-   <summary>Example: POST request to create a new resource using flat attributes (JSON patch syntax) eg. for a simple Wordpress contact-form</summary>
-
-```
-cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/' -X POST -d @- -H "Content-Type: application/json" --user <username>
-{
-  "fullName": "First Tester",
-  "name/personal": "First",
-  "name/surname":  "Tester",
-  "organizations/org/name": "Test Organization",
-  "emails/work": "test.user@test-user.org",
-  "addresses/work/locality": "Test-Town",
-  "addresses/work/postcode": "12345",
-  "addresses/work/street": "Teststr. 123",
-  "addresses/work/country": "Germany",
-  "addresses/work/countryCode": "DE",
-  "phones/tel_work": "+49 123 4567890",
-  "online/url": "https://www.example.org/",
-  "notes/note": "This is a note.",
-  "egroupware.org:customfields/Test": "Content for Test"
-}
-EOF
-
-HTTP/1.1 201 Created
-Location: https://example.org/egroupware/groupdav.php/<username>/addressbook/1234
-```
-</details>
-
-* **PUT**  requests with  a ```Content-Type: application/json``` header allow modifying single resources (requires to specify all attributes!)
-
-<details>
-   <summary>Example: PUT request to update a resource</summary>
-
-```
-cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/1234' -X PUT -d @- -H "Content-Type: application/json" --user <username>
-{
-  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
-  "prodId": "EGroupware Addressbook 21.1.001",
-  "created": "2010-10-21T09:55:42Z",
-  "updated": "2014-06-02T14:45:24Z",
-  "name": [
-    { "type": "@type": "NameComponent", "personal", "value": "Default" },
-    { "type": "@type": "NameComponent", "surname", "value": "Tester" }
-  ],
-  "fullName": { "value": "Default Tester" },
-....
-}
-EOF
-
-HTTP/1.1 204 No Content
-```
-</details>
-
-<details>
-   <summary>Example: PUT request with UID to update an existing resource or create it, if not exists</summary>
-
-```
-cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/5638-8623c4830472a8ede9f9f8b30d435ea4' -X PUT -d @- -H "Content-Type: application/json" --user <username>
-{
-  "uid": "5638-8623c4830472a8ede9f9f8b30d435ea4",
-  "prodId": "EGroupware Addressbook 21.1.001",
-  "created": "2010-10-21T09:55:42Z",
-  "updated": "2014-06-02T14:45:24Z",
-  "name": [
-    { "type": "@type": "NameComponent", "personal", "value": "Default" },
-    { "type": "@type": "NameComponent", "surname", "value": "Tester" }
-  ],
-  "fullName": { "value": "Default Tester" },
-....
-}
-EOF
-```
-Update of an existing one:
-```
-HTTP/1.1 204 No Content
-```
-New contact:
-```
-HTTP/1.1 201 Created
-Location: https://example.org/egroupware/groupdav.php/<username>/addressbook/1234
-```
-</details>
-
-
-* **PATCH** request with a ```Content-Type: application/json``` header allow to modify a single resource by only specifying changed attributes as a [PatchObject](https://www.rfc-editor.org/rfc/rfc8984.html#type-PatchObject)
-
-<details>
-   <summary>Example: PATCH request to modify a contact with partial data</summary>
-
-```
-cat <<EOF | curl -i 'https://example.org/egroupware/groupdav.php/<username>/addressbook/1234' -X PATCH -d @- -H "Content-Type: application/json" --user <username>
-{
-  "name": [
-    {
-      "@type": "NameComponent",
-      "type": "personal",
-      "value": "Testfirst"
-    },
-    {
-      "@type": "NameComponent",
-      "type": "surname",
-      "value": "Username"
-    }
-  ],
-  "fullName": "Testfirst Username",
-  "organizations/org/name": "Test-User.org",
-  "emails/work/email": "test.user@test-user.org"
-}
-EOF
-
-HTTP/1.1 204 No content
-```
-</details>
-
-* **DELETE** requests delete single resources
-
-* one can use ```Accept: application/pretty+json``` to receive pretty-printed JSON eg. for debugging and exploring the API
-
-#### Implemented [changes from JsContact draft 08](https://github.com/rsto/draft-stepanek-jscontact/compare/draft-ietf-jmap-jscontact-08):
-* localizedString type / object is removed in favor or regular String type and a [localizations object like in JsCalendar](https://datatracker.ietf.org/doc/html/rfc8984#section-4.6.1)
-* [Vendor-specific Property Extensions and Values](https://datatracker.ietf.org/doc/html/draft-ietf-jmap-jscontact-07#section-1.3) 
-use ```<domain-name>:<name>``` like in JsCalendar
-* top-level objects need a ```@type``` attribute with one of the following values: 
-```NameComponent```, ```Organization```, ```Title```, ```Phone```, ```Resource```, ```File```, ```ContactLanguage```, 
-```Address```, ```StreetComponent```, ```Anniversary```, ```PersonalInformation```
-
 ### ToDos
 - [x] Addressbook
   - [ ] update of photos, keys, attachments
 - [ ] InfoLog
-- [X] Calendar
+- [X] Calendar (recurring events and alarms are readonly)
+  - [ ] support creating and modifying recurring events and alarms
+- [X] Mail
+  - [ ] querying received mails
 - [ ] relatedTo / links
 - [ ] storing not native supported attributes eg. localization
\ No newline at end of file