The Generic String Master (GSM) translation table and its related tables can be modified to add an additional character subset to be used in picture string processing by the ISPF EDIT, FIND, and CHANGE commands.

These steps allow you to modify the GSM to use a character subset:

1. Choose which character is used to represent your subset. For example, Edit uses an @ to stand for alphabetic.
2. Modify the entry in the Generic String Special Character (GSS) table found in Translation table for generic string special characters corresponding to the character you wish to use for a value of X'08'. This indicates where in the Generic String Character Code (GSC) table the mask for your character set is located. The GSC does not need to be changed as it is initially set for user character sets.
3. Modify the GSM entries of those characters you wish to include in your special character set so the high order bit is on.