The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location. FPMap (Free Page Map) Page


The general layout of an FPMap is identical to that of an AMap, except that each bit in the FPMap corresponds to a PMap page, and the value of the bit indicates whether there are any free pages within that PMap page. With each PMap covering about 2 megabytes and an FPMap page at 496 bytes, an FPMap page covers about 8 gigabytes of space.

Implementations SHOULD NOT use FPMaps. The Density List SHOULD be used for location free space.<17> However, the presence of FPMap pages at the correct intervals MUST be preserved, and all corresponding checksums MUST be maintained for a PST file to remain valid.