Annex A (informative) Grammar summary [gram]

A.9 Derived classes [gram.derived]

base-clause:
    : base-specifier-list
base-specifier-list:
    base-specifier ...opt
    base-specifier-list , base-specifier ...opt
base-specifier:
    attribute-specifier-seqopt base-type-specifier
    attribute-specifier-seqopt virtual access-specifieropt base-type-specifier
    attribute-specifier-seqopt access-specifier virtualopt base-type-specifier
class-or-decltype:
    nested-name-specifieropt class-name
    decltype-specifier
base-type-specifier:
    class-or-decltype
access-specifier:
    private
    protected
    public