(Have you read "help t-concepts", "help t-rooms", and "help t-locks",
yet? If not, you should read them first.)
Sometimes you'll want to create a verb that doesn't do anything
except print text on the screen. You don't want it to actually take
you anywhere when you type it, or actually do anything. Verbs like
this are called 'fake actions'.
You can create these in the same way as normal exits. Let's say
you're in your living room. You have a couch here, and you'd like
people to be able to sit on the couch. You start by opening an exit
to nowhere (dbref #-3). You do this by typing "@open sit;sit on
couch;sit down;sit on the couch=nowhere". Now, to prevent 'sit' from
appearing in the 'Visible Exits:' list, type "@set sit=dark". Last,
you just need to set the @success and @osuccess messages appropriately
("@success sit=You sit down.", "@osuccess sit=sits on the couch.").
[Type "help t-verbs2" for more information.]