I did this with LaTeX and memoir: in my case, I only wanted a shorter title 
in the page headings. I kept the full title in the table of contents. These 
are the relevant functions from my filter:

-- Print a formatted warning to stderr

function warnf (...)

  io.stderr:write(string.format(...))

end

function Header (el)

  -- Replace heading with raw LaTeX if pageheading is used to specify a

  -- shorter form of the title to use in page headers.

  if el.attributes.pageheading then

    local commands = {'chapter', 'section', 'subsection'}

    if el.level > #commands then

      warnf('pageheading attribute not supported for level %d headings', 
el.level)

      return el

    end

    -- Produce LaTeX like pandoc does, but with two additional arguments

    -- to specify a short for of the page heading to memoir.

    local title = pandoc.utils.stringify(el)

    local latexStr = string.format('\\%s[%s][%s]{%s}', commands[el.level], 
title, el.attributes.pageheading, title)

    local label = string.format('\\label{%s}', el.identifier)

    -- wrap in hypertarget

    latexStr = string.format('\\hypertarget{%s}{%%\n%s%s}', el.identifier, 
latexStr, label)

    return pandoc.RawBlock('latex', latexStr)

  end

end


On Wednesday, June 30, 2021 at 1:37:00 AM UTC+2 John MacFarlane wrote:

>
> Not easy. You could write a filter that builds the
> relevant section command, but that might break other
> things because the LaTeX writer won't see a heading
> there (not sure).
>
> It might be a good idea to have pandoc do this automatically.
>
> "'Nick Bart' via pandoc-discuss"
> <pandoc-...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org> writes:
>
> > Is there any way to have pandoc output LaTeX code like
> >
> > \section[Short Section Title]{Long Section Title}
> >
> > from pandoc markdown containing both versions as in the following (but 
> not necessarily given in this exact syntax)?
> >
> > # Long Section Title {short_title="Short Section Title"}
> >
> > -- 
> > You received this message because you are subscribed to the Google 
> Groups "pandoc-discuss" group.
> > To unsubscribe from this group and stop receiving emails from it, send 
> an email to pandoc-discus...-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> > To view this discussion on the web visit 
> https://groups.google.com/d/msgid/pandoc-discuss/4p2Sx0e_CqUgNm9ZcXR064fya9gybYYDVBTVMMIL9p1m2ynHgBzs30shkkVJnu0l2RqSKghQo5oi10jSV33BS6IBsvIhBhtyoExu-d3p3Kc%3D%40protonmail.com
> .
>

-- 
You received this message because you are subscribed to the Google Groups "pandoc-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pandoc-discuss+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit https://groups.google.com/d/msgid/pandoc-discuss/bc3ac76b-306d-4ab4-9a33-6acdd2d2a38fn%40googlegroups.com.