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. There are still certain compatibility issues between the two COBOL systems, which are detailed, with any possible workarounds, in the RM/COBOL Conversion Issues section.