REXX called my COBOL - file status 96 - forgot ALLOC?

ADDRESS TSO CALL to a COBOL module. Program opens a sequential file and dies with status 96 / IGZ0035S.

In the REXX I never ALLOC'd that DD. That the whole story?

Whole story. COBOL ASSIGN TO MYDD needs MYDD allocated in the TSO session before CALL.

"ALLOC FI(MYDD) DA('HLQ.DATA') SHR REUSE" then call. FREE when done.

Allocated the DD. COBOL ran. I knew this and still forgot.