Indexing formatted text?

[dkg]

draft-ietf-lamps-header-protection uses several terms that always show up as formatted text, like:

`hp="cipher"`

It would be nice if each time hp="cipher" showed up, it would link back to the section that describes this Content-Type parameter.

I tried adding it to the index like this:

*[hp="cipher"]: #hp-parameter

And i tried adding it to the index like this:

*[`hp="cipher"`]: #hp-parameter

But in neither case did it show up in the index, or provide cross-linkage in the document. Do i need to choose between having the string indexed automagically and having it appear in <spanx style="verb"> form? Or is there some way i can get kramdown to give me both?