In order for FCM to operate on a file properly, it needs to know which template is associated with the file and whether it should operate automatically at creation, load, or save time. The process by which FCM gathers this information is called buffer qualification (“buffer” because FCM obviously operates on file buffers). Whether FCM should operate at create, load, or save-time is called a behavior.
We said in the introduction that template variables may be set to automatically expand at those different times, so you may wonder why the additional information is required. In fact, it is not really required, but there may be times where you would rather skip the expansion process altogether, regardless of any template variable setting. In other words, the create, load, or save behaviors act as global switches.