COMBINING OVER MARK?

Hi All,

Attached is a part of page 36 of Henry Alford's *The Queen's English: a
manual of idiom and usage (1888)* [
http://archive.org/details/queensenglishman00alfo]

Is the way to indicate alternative s/z spellings used there plain text
(arguably, if it can be done with a typewriter, it is plain text) or rich
text (ignoring the font size of letters s and z)?

If it's the latter, what's the markup to achieve it? If it can be
considered plain text, then "anathemati<small>s<COMBINING OVER
MARK>z</small>e" could be considered.

IIRC, there was a similar discussion or a proposal concerning atomic masses
and numbers of chemical elements that are traditionally typeset in a
similar way.

What happened to it?

Thanks,
Leo