diff --git a/docs/rolereference.rst b/docs/rolereference.rst
index a9327a6f3ca810908e1d411ad884de32f3f3b64e..95f17efbe44fc45134adca31e59c774c324dc26c 100644
--- a/docs/rolereference.rst
+++ b/docs/rolereference.rst
@@ -2280,6 +2280,9 @@ Duply is configured as follows:
 * Volume size is set to 1GB.
 * Pre-backup scripts are run via ``/etc/duply/main/pre`` handler that tries to
   execute scripts/binaries from directory ``/etc/duply/main/pre.d/``.
+* Pre-backup scripts must run successfully for the actual backup
+  process to proceed.
+* Old backups are automatically purged in case of successful run.
 
 .. note::
    Since at time of this writing there are no lookup plugins for extracting key