Let me object to introducing \textit for anything new. If we clearly mark all semantic things appropriately, we can easily fix the font later. Going \textit gets us back to where we've been all along: unable to add index entries for term definitions, for example.

In any case, I'd like to point out that we sometimes use the code placeholder and mention it in regular text to explain what it means. That's probably an argument against different fonts for these.

I think that's a red herring: code placeholders should always appear in code placeholder font (typewriter + decoration), whether that's in a code block or in body text. The things I want to distinguish are conceptual placeholders (like "a memory access A") and meta variables (like type).

Ok. Whatever the outcome, we should be clear what to use in "A is sequenced before B" vs. "offsetof(type, member-designator" vs. "atomic<integral>" (the latter doesn't even say "T"). If we can clearly differentiate these uses, let's introduce a \metavar for the first case NOW and discuss formatting later.

The other option that I hinted at is that we can use \placeholder for both, and since the latter usage always appears in a code font setting, we could make the macro smarter to distinguish the two use cases and select the desired style accordingly. In some sense, both uses are kinds of placeholders (just with somewhat different usage).

Editorial meeting consensus: Maybe use "I" as the placeholder, not "integral". Use slanted font for \tcode bool, where necessary. Ask LWG for feedback.

See #2245.