STANDARD.SELECTION & PGM.FILE

See helptext :-)
STANDARD.SELECTION
This file defines the layout of the data dictionaries and the alternate indices for all files on the system.
The fields in the STANDARD.SELECTION record are split into two parts System and User defined. All the system (T24) defined fields begin with SYS and cannot be modified. The user defined fields begin with USR.
The dictionary and alternate indices for the data file are built when the STANDARD.SELECTION record is 'Authorised'.
Note: The building of alternate indices requires the EXCLUSIVE use of the data file and should only be carried out when there are no other users on the system.

PGM.FILE
This file is an inventory of all T24 programs or processes that can be run from the action line, run from within the BATCH.CONTROL environment, or used in the execution of report programs written using the T24 report generator.
Whenever an application or batch job is selected, the PGM.FILE table is read to firstly see if the program or process exists, and secondly to see what its characteristics are. If there is no entry on the PGM.FILE table then it cannot be executed from within the T24 environment. If there is an entry then the system reviews its characteristics to ascertain:

(i)What type of process is it? e.g. - is it only to be executed from the batch system? - does it maintain history?
(ii)What is the screen title?
(iii)Are there any special characteristics. e.g. - should the ! function be disabled?
(iv)If it is a batch job what is the actual program that is to be run?

This table can also hold the names of all subroutines within T24 (i.e. programs that are used but cannot be accessed from the action line), and routines that are referenced by the report generator.
However it is not recommended that this file should contain all subroutines and hence be a complete inventory of all T24 software because

(i) there are better ways of maintaining an inventory of programs;
(ii) the size of the file, which is continually being referred to, would be larger than it need be.

Only the subroutines likely to be used by any report generator record should be loaded into this file.