Clarify the difference between outdated and redundant snapshots.

diff --git a/dss.ggo b/dss.ggo
index a6644ee3954222db0ed21a568e0ce8e0717e7763..d843906bf718906944fa46bd5e22687f9e14149a 100644 (file)
--- a/dss.ggo
+++ b/dss.ggo
@@ -107,13 +107,14 @@ details="
 
 groupoption "prune" P
 #~~~~~~~~~~~~~~~~~~~~
-"Remove a redundant snapshot"
+"Remove redundant and outdated snapshots"
 group="command"
 details="
-       A snapshot is considered redundant if it ether belongs to
-       an interval greater than the maximum number of intervals,
-       or if it belongs to an interval that already contains more
-       than the desired number of snapshots.
+       A snapshot is considered outdated if it belongs to an interval
+       greater than the maximum number of intervals. It is said to be
+       redundant if it belongs to an interval that already contains
+       more than the desired number of snapshots. This command gets
+       rid of such snapshots.
 "
 
 groupoption "ls" L