In the syntax notation used in this International Standard, syntactic categories are indicated by italic type, and literal words and characters in constant width type. Alternatives are listed on separate lines except in a few cases where a long set of alternatives is marked by the phrase “one of.” If the text of an alternative is too long to fit on a line, the text is continued on subsequent lines indented from the first one. An optional terminal or non-terminal symbol is indicated by the subscript “opt”, so
{ expressionopt }
indicates an optional expression enclosed in braces.
Names for syntactic categories have generally been chosen according to the following rules:
X-name is a use of an identifier in a context that determines its meaning (e.g., class-name, typedef-name).
X-id is an identifier with no context-dependent meaning (e.g., qualified-id).
X-seq is one or more X's without intervening delimiters (e.g., declaration-seq is a sequence of declarations).
X-list is one or more X's separated by intervening commas (e.g., expression-list is a sequence of expressions separated by commas).