How to add markup to author information in document title

Because lawyers, I need to do something like this:

= A Trademarked^(TM)^ Title
Editors: A Registered^(R)^ Editor

Unfortunately, the title is formatted with a superscript (TM) in html5 output, but the editor line shows the literal markup. Is there a way to accomplish this?

This seems to work:

= A Trademarked^(TM)^ Title
:R: pass:q,r[^(R)^]
Editors: A Registered{R} Editor

I think this issue is due to it being in a header--where, if I gather correctly, only "Special Characters" and "Attributes" get replaced. But having an attribute entry above the author line doesn't disrupt; because, "Attribute entries can be placed anywhere in the header" (https://asciidoctor.org/docs/user-manual/#doc-header).

Thanks! Very helpful.

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