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The three-letter mnemonic can be used to group similar coding practices and to indicate to which category a coding practice belongs to.
The numeric value is used to give each coding practice a unique identifier. Numeric values in the range of 00 to 29 are reserved for recommendations, and values in the range of 30 to 99 are reserved for rules. Rules and recommendations are frequently referenced from the rules in this standard by their identifier and title.
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