Index File - Free Space Record

The free space record points to the location of free records in the index file or data file (fixed-length files only). Continuation records of the same size and structure are created as needed, each pointing to the next continuation record.

The first free space record is pointed to by the file header.

A free space record contains:

Size	Description
2	Record header. Present only if index nodes have record header (see the topic Types of Indexed File).
2	Bit 15 Security Flag. Value should match value of trailing security flag. Bits 14-0 Pointer to the end of the last free record address entry, relative to the start of this record.
`file-pointer-size`	Offset of free space continuation record. Zero if no further continuation records.
`file-pointer-size`	Offset of a free record in the index file.
...
`file-pointer-size`	Offset of a free record in the index file.
2	Bit 15 Security flag. Value should match value of leading security flag. Bits 14-0 Reserved. Value x"7F".

The size of file-pointer-size varies according to the type of indexed file. See the topic Types of Indexed File for details.