3 regularly used IMS DC commands that i have come accross (and used)are
1) /FORMAT :- USe this command whenever you want to use the Message Format Service(MFS). Syntax :- /FORMAT <modname>
2) /TEST :- Whenver you want to test your MFS blocks, put them in the PDS named IMS*.TFORMAT and give a /TEST MFS at the terminal . then give /FOR followed by the MOD name
3) regular transactions. These transaction codes are associated with a program name. Use them to invoke programs.
/DIS TRAN tranname itself diplay the PSB-NAME.
In General we use the same name for the PSB and TRAN
/DIS TRAN pgmname is Invalid according to my knowledge
/DIS PROG pgmname will displays the Transaction associated with this program and type of PSB=TP/DB.