Packed Lookup

Every record in the database has an entry in the lookup table. These entries are formatted as follows:

Offset  Name     Type      Contents 
------  -------  --------  --------
0...1   Size     int       Size of record (including record header) 
2...3   Filters  int       If bit 0x0001...0x8000 is set, this indicates that a switch
                           to viewpoint 0...15 requires this record to be sorted/filtered
                           afresh.  Filters gives the "dirty bit" for keeping track of
                           what records have been changed since last visiting a
                           viewpoint.  
4       Flags     char     128 = Deleted 
5...7   Offset    char[3]  3 bytes of offset (0...16 M) Lowest...Highest Offset gives
                           disk seek address of record.