OP_UNDELETE "undelete the current entry"
OP_UNDELETE_THREAD "undelete all messages in thread"
OP_UNDELETE_SUBTHREAD "undelete all messages in subthread"
-OP_VERSION "show the Mutt version number and date"
OP_VIEW_ATTACH "view attachment using mailcap entry if necessary"
OP_VIEW_ATTACHMENTS "show MIME attachments"
OP_MAIN_SHOW_LIMIT "show currently active limit pattern"