Method of Selecting Whether a Post is put on FaceBook or Not.

Hi,

identi.ca offers the service of update your facebook status while the identi.ca status changes.
This feature is very useful but sometimes you need to post a message on identi.ca only (for example a message to a group, or something you don't want to post on facebook).

A pattern at the beginning of the sentence that if it's recognized it posts to facebook too would be appreciate in this situation. eg:

fb this message will go to facebook too

thanks