category tag".

The new text was present in the Ranges wording, but with no insertion /
deletion markup to indicate that an edit was to be performed. However,
consultation with LWG revealed that this was an intentional edit missing
markup.

on type that cannot be const-qualified.

This form of requirement was made ill-formed by P1084R2. In its place,
use { I } -> Same<T&>, after discussion on the lib reflector.

Replace requirement
  E; requires C<decltype((E)), Args>;
with
  { E } -> C<Args>;
in requires-expressions added by P0896R4. Likewise for cases where
decltype(E) is used and means the same thing, and for cases where
Same<T, decltype((E))> is used (which means the same thing because
Same is symmetric).

Fixes #2507.