If in an input file I have
\input texinfo
@node Top
@top
@cindex @'e @'e
@printindex cp
@bye
And then I run
texi2any test.texi --html --no-split --disable-encoding
the output file has a letter heading "E":
<tr><th><a name="Top_cp_letter-E">E</a></th><td></td><td></td></tr>
But with
texi2any test.texi --html --no-split --enable-encoding
I get a heading "É":
<tr><th><a name="Top_cp_letter-É">É</a></th><td></td><td></td></tr>
I believe this is out-of-scope for the --disable-encoding option, as
the manual says:
'--disable-encoding'
'--enable-encoding'
By default, or with '--enable-encoding', output accented and
special characters in Info and plain text output based on
'@documentencoding'. With '--disable-encoding', 7-bit ASCII
transliterations are output. *Note @documentencoding::, and *note
Inserting Accents::.
Nothing there about letter headings in HTML.
Would I be correct in thinking that "E" is the correct heading to use?
"E" would be used if the index entries were sorted with sort keys that
only included ASCII characters (no accented characters, for example).
As far as I remember, that's what texinfo.tex and texindex do.