The ENTER statement is classed as an obsolete element in the ANSI'85 standard and is scheduled to be deleted from the next full revision of the ANSI Standard.
All dialects in this COBOL implementation support this syntax for documentation purposes only. The FLAGSTD Compiler directive can be used to detect all occurrences of this syntax.
Although it is a part of the standard COBOL definition, this feature is explicitly excluded from the X/Open COBOL language definitions and should not be used in an X/Open COBOL conforming source program.