FORTRAN77 does not keep track of environments for INTERACTIVEXREF; therefore, no environment information is included in the header line. The ENVIRONMENTS and GLOBALENVIRONMENTS options are not available, nor are any of the environment ranges, identifier environment ranges, or identifier qualifications—with the exception of AT FIRST and AT <sequence number>.

The EXPAND command is not available when INTERACTIVEXREF is run against FORTRAN77 programs.

A number (FORTRAN77 label) or an identifier containing dollar signs ($) is accepted as a valid identifier when FORTRAN77 XREFFILES are loaded.