15.3 ...........  FUNCTIONS BY CATEGORY. 
15.3.1 ......... Date Function.
15.3.2 ......... Database Functions.
15.3.3 ......... Low-level File I/O.
15.3.3a ........ Buffered I/O Open Modes Table.
15.3.3b ........ Binary I/O Open Modes Table.
15.3.4 ......... Cursor/Print Head Functions.
15.3.5 ......... Input/Output Functions.
15.3.6 ......... Memo Function.
15.3.6a ........ Memo Open Modes Table.
15.3.7 ......... String Functions.
15.3.8 ......... System Functions.
15.3.9 ......... Pick List Functions.
15.3.10 ........ TSR Functions.
15.3.11 ........ Miscellaneous Functions.