DEC STD 164

This document, DEC Standard 164, Revision A, titled "Software Use of the Graphic Character Set of ASCII," defines a specific subset of the ASCII graphic character set intended for use by Digital Equipment Corporation (DEC) software products.

The primary purpose of the standard is to ensure international compatibility by standardizing the characters that are assigned special semantic meaning (e.g., as delimiters in command or programming languages) in DEC software and documentation. This is crucial because the graphic representation of certain ASCII characters can vary across national character sets and keyboards.

The standard:

• Applies to the implementation of new software products and extensions to existing ones.
• Does not apply to user-defined character strings, constants, variables, or data.
• Lists the graphic characters included in the standard, providing their ASCII names and, for informational purposes, their common usage in DEC's Digital Command Language (DCL).
• Identifies specific ASCII characters that are excluded from the standard because they are reserved for "national use graphics" and their appearance/meaning varies by country.
• Specifies conformance rules, allowing exceptions for compatibility with existing products or adherence to other national/international standards, provided that equivalent characters from the included set or keywords are supported if excluded national-use characters are implemented.