When a keyed file is created using SRTSEQ and LANGID, the SRTSEQ specified is used when comparing character keys in the file during CHAIN, SETLL, SETGT, READE and READPE operations. You do not have to specify the same, or any, SRTSEQ value when creating the RPG program or module.
When a value for SRTSEQ is specified on CRTBNDRPG or CRTRPGMOD, then all character comparison operations in the program will use this SRTSEQ. This value affects the comparison of all fields, including key fields, fields from other files and fields declared in the program.
You should decide whether to use SRTSEQ for your RPG program based on how you want operations such as IFxx, COMP, and SORTA, to work on your character data, not on what was specified when creating your files.