Suggested resolution:

Change in 6.4.1 [basic.scope.scope] bullet 5.1 as follows:

A declaration is name-independent if its name is _ (u+005f low line) and it declares

• a variable with automatic storage duration other than a function parameter,
• a structured binding with no storage-class-specifier and not inhabiting a namespace scope,
• the variable introduced by an init-capture, or
• a non-static data member of other than an anonymous union.

(From submission #681.)

According to P2169R4 (A nice placeholder with no name):

In Varna, EWG decided not to support function parameter names and requires clauses param-eter as these can remained unamed without semantics differences.

However, the normative wording does permit function parameters to be name-independent, contrary to the express design intent.