Messages in Rational Developer for System are of the format CRRZcnnnnL, where CRRZ is the prefix for Rational Developer for System z, c is a letter that indicates a particular component, nnnn is a message number unique in that component, and L is the message level. The message level can have values S for severe errors, E for error, W for warning, and I for informational.
Host message IDs have the format CRAZnnnnL.