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3.1 File format

An RCS file’s contents are described by the grammar below⁴. Overall, the format is free–format text. In most environments RCS uses the ISO 8859/1 encoding: visible graphic characters are (octal) codes 041–176 and 240–377, and whitespace characters are codes 010–015 and 040.
TODO:  Discuss or point to encoding compatibility issues.

• File format grammar
• Additional particulars of the file format