Marked For Later. Used on Internet forums to mark a topic of interest to the user that he/she may not be able to view at the current moment (i.e., the user is at work and the topic contains a link that isn't safe for work).
By marking the topic with a post, the user can go back later and, usually by using a "My Latest Posts" feature, view the content.
Topic: Nekkid JAlba Pics
Poster 1: *fap* *fap* *fap*
Poster 2: At work... mfl