diff --git a/doc/man/task.1.in b/doc/man/task.1.in
index 684143e74..d6f8d2f51 100644
--- a/doc/man/task.1.in
+++ b/doc/man/task.1.in
@@ -376,6 +376,14 @@ Modifies the existing task with provided information.
 .B task <filter> prepend <mods>
 Prepends description text to an existing task.
 
+.TP
+.B task <filter> purge
+Permanently removes the specified tasks from the data files. Only
+tasks that are alredy deleted can be purged. This command has a
+local-only effect and changes introduced by it are not synced.
+
+Warning: causes permanent, non-revertible loss of data.
+
 .TP
 .B task <filter> start <mods>
 Marks the specified tasks as started.