diff --git a/docs/content/configuration/jobs.md b/docs/content/configuration/jobs.md
index 476236e..50621a7 100644
--- a/docs/content/configuration/jobs.md
+++ b/docs/content/configuration/jobs.md
@@ -37,6 +37,11 @@ This is temporary and being worked on {{< zrepl-issue 24 >}}.
 
 A source job is the counterpart to a [pull job]({{< relref "#pull" >}}).
 
+Note that the prune policy determines the maximum replication lag:
+a pull job may stop replication due to link failure, misconfiguration or administrative action.
+The source prune policy will eventually destroy the last common snapshot between source and pull job, requiring full replication.
+Make sure you read the [prune policy documentation]({{< relref "configuration/prune.md" >}}).
+
 Example: {{< sampleconflink "pullbackup/productionhost.yml" >}}
 
 ### Pull
diff --git a/docs/content/configuration/prune.md b/docs/content/configuration/prune.md
index 9be96da..1036cf9 100644
--- a/docs/content/configuration/prune.md
+++ b/docs/content/configuration/prune.md
@@ -48,3 +48,13 @@ The following procedure happens during pruning:
     1. the contained snapshot list is sorted by creation.
     1. snapshots from the list, oldest first, are destroyed until the specified `keep` count is reached.
     1. all remaining snapshots on the list are kept.
+
+{{% notice info %}}
+The configuration of the first interval (`1x1h(keep=all)` in the example) determines the **maximum allowable replication lag** between source and destination.
+After the first interval, source and destination likely have different retention settings.
+This means source and destination may prune different snapshots, prohibiting incremental replication froms snapshots that are not in the first interval.
+
+**Always** configure the first interval to **`1x?(keep=all)`**, substituting `?` with the maximum time replication may fail due to downtimes, maintenance, connectivity issues, etc.
+After outages longer than `?` you may be required to perform **full replication** again.
+{{% / notice %}}
+