Some rules are omitted in [dcl.ptr], [dcl.ref], [dcl.mptr], [dcl.array], [dcl.fct]

the type of the declarator-id in D is “derived-declarator-type-list noexcept _opt function of parameter-type-list cv-qualifier-seq _optref-qualifier_opt returning T”, where...

The type of the declarator-id in D is “derived-declarator-type-list noexcept_optfunction of parameter-type-list cv-qualifier-seq _optref-qualifier_optreturning U”, where..

A type of either form is a function type.

How about if "derived-declarator-type-list" is not empty(e.g, "pointer to" )? Is it, in either case, a function type? It obviously not. I think it should be:

A type of either form is a function type if the derived-declarator-type-list is empty.

The following rule is used to state what kind of declaration declares a function, It emphasizes that a typedef declaration with function type does not declare a function, which is a lack in the standard.

a function declaration declares a function.

It should have the similar modification for [dcl.ptr], [dcl.ref], [dcl.mptr], [dcl.array].

[dcl.ptr]

the type of the declarator-id in D is “derived-declarator-type-list cv-qualifier-seq pointer to T”.

The type is a pointer type if the derived-declarator-type-list is empty. An object declaration with the pointer type declares a pointer.

[dcl.ref]

the type of the declarator-id in D is “derived-declarator-type-list reference to T”

The type is a reference type if the derived-declarator-type-list is empty. An object declaration with the reference type declares a reference.

[dcl.mptr]

the type of the declarator-id in D is “derived-declarator-type-list cv-qualifier-seq pointer to member of class nested-name-specifier of type T”

The type is a pointer-to-member type if the derived-declarator-type-list is empty. An object declaration with the pointer-to-member type declares a pointer to member.

[dcl.array]

the type of the declarator-id in D is “derived-declarator-type-list array of N T”.

The type is an array type if the derived-declarator-type-list is empty. An object declaration with the array type declares an array.

The above modification together with the following rule simultaneously clarifies that a typedef declaration with a reference type or an object type does not declare a variable, for which I don't find any strong evidence in the current draft; Since there is no rule in the current draft states what is the declaration of a reference or an object.

If the decl-specifier-seq contains no typedef specifier, the declaration is called a function declaration if the type associated with a declarator-id is a function type ([dcl.fct]) and an object declaration otherwise.

Start by comparing the quoted wording in [dcl.fct], [dcl.ptr], [dcl.ref], [dcl.mptr], and [dcl.array]. Check how derived-declarator-type-list and typedef declarations are described across these clauses, then verify that the proposed conditions consistently distinguish function, pointer, reference, pointer-to-member, and array types. Done means the wording is internally consistent and the declaration cases are unambiguous.