COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

Syntax Diagram Conventions
This manual presents syntax in railroad diagrams. Here is a generic railroad diagram:
To use a railroad diagram, follow the direction of the arrows and specify syntactic items as indicated
by the diagram pieces:
MeaningDiagram Piece
Type KEYWORD as shown. You can type letters in
uppercase or lowercase.
Replace item with a value that fits its description, which
follows the syntax diagram.
Type content (punctuation mark, symbol, or letter) as shown.
You can type a letter in uppercase or lowercase.
The 1985 COBOL standard classifies item as obsolete,
so you are advised not to use it. (An obsolete keyword is
marked the same way; that is, «KEYWORD».)
«item»
Some examples of the meanings of simple diagrams are:
MeaningDiagram Piece
Choose item1 or item2.
Choose item1, item2, or neither.
Notation Conventions 31