+Specify the new name for this contact.
+
+*-e*, *--expiration*::
+Set expiration time of messages (seconds).
+To disable expiration set expiration time to 0.
+
+=== block
+
+Block the given contacts or groups (no messages will be received).
+This change is only local but can be synchronized to other devices by using `sendContacts` (see below).
+
+[CONTACT [CONTACT ...]]::
+Specify the phone numbers of contacts that should be blocked.
+
+*-g* [GROUP [GROUP ...]], *--group* [GROUP [GROUP ...]]::
+Specify the group IDs that should be blocked in base64 encoding.
+
+=== unblock
+
+Unblock the given contacts or groups (messages will be received again).
+This change is only local but can be synchronized to other devices by using `sendContacts` (see below).
+
+[CONTACT [CONTACT ...]]::
+Specify the phone numbers of contacts that should be unblocked.
+
+*-g* [GROUP [GROUP ...]], *--group* [GROUP [GROUP ...]]::
+Specify the group IDs that should be unblocked in base64 encoding.
+
+=== sendContacts