There is an idea in the CA Mainframe Application Quality & Testing Tools Community for this:
In CA SymDump CICS "Abend Help", replace the CAIN1904 message with "No help is available for this abend code" for ABEND codes not yet in the Help file.
When we select "Abend Help" from the CA SymDump for CICS panels for a dump that has no ABEND code, we get this CAIN1904 message:
CAIN1904 (*) FUNCTION - END OF FILE.
While you were browsing a file, an end of file condition occurred.
Either enter 'PREV' or a previous code, or browse using a different key, or end this file function.
It would be nice if we got the more standard "No help is available for this abend code." message.