By default, this COBOL system already supports much of the RM/COBOL syntax and behavior. Additional RM/COBOL-specific syntax that has been added for compatibility is documented in the section RM/COBOL Syntax Support in your Language Reference.
You can also enable additional RM/COBOL behavior using certain Compiler directives. Using these directives when you submit your RM/COBOL source programs to this COBOL system ensures that most of the programs are accepted the first time they are submitted; however, they are only intended for use in a native COBOL environment. There are still certain compatibility issues between the two COBOL systems, which are detailed, with any possible work-arounds, in the RM/COBOL Conversion Issues section.