--- a/share/local-bsdtools/common.subr	Mon May 06 09:32:14 2024 +0200
+++ b/share/local-bsdtools/common.subr	Tue May 07 09:32:43 2024 +0200
@@ -74,10 +74,22 @@
 }
 
 
+#:
+#: Use `mount -t zfs -p` to determine the ZFS dataset for a given mountpoint
+#:
+#: Args:
+#:  $1: the mountpoint
+#:
+#: Output (stdout):
+#:   The name of the ZFS dataset that is mounted on `$1`
+#:
+#: Return:
+#:   - 0 if a mounted dataset is found
+#:   - 1 if no ZFS dataset is found that is mounted on `$1`
+#:
+#: The dataset has to be mounted.
+#:
 _get_zfs_dataset_for_mountpoint() {
-    : 'Use `mount -t zfs -p` to determine the ZFS dataset for a given mountpoint.
-
-    '
     local _mountpoint
 
     local _ds _mount _rest
@@ -97,12 +109,27 @@
 }
 
 
+#:
+#: Determine the ZFS dataset that is mounted at `$1`/var/empty.
+#:
+#: Allow special handling for <mountpoint>/var/empty which may be
+#: mounted read-only.
+#:
+#: Args:
+#:  $1: the root mountpoint
+#:
+#: Output (stdout):
+#:   The name of the ZFS dataset that is mounted on `$1`/var/empty
+#:
+#: Return:
+#:   - 0 if a mounted dataset is found
+#:   - 1 if no ZFS dataset is found that is mounted on `$1`
+#:
+#: The dataset has to be mounted.
+#:
 _get_zfs_dataset_for_varempty() {
-    : 'Allow special handling for <mountpoint>/var/empty which may be
-    mounted read-only.
+    local _mountpoint
 
-    '
-    local _mountpoint
     local _ve_mount
 
     _mountpoint="$1"