# Changes

,  20:10, 8 June 2020
no edit summary
ConTeXt offers the possibility to have mirrored headers (for odd and even pages); content can be in two parts, at the inner and outer margin of each page. But how do you get a header that will have one part of its content centered and one part in the outer margin? (This is a common setup for books: chapter title centered, page number in outer margin.) Hans posted this solution to the list:
</texcode>
The use of the TeX macros {{cmd|rlap }} and {{cmd|llap }} allows centering of content. Note that {{cmd|pagenumber}} gets you the number prior to conversion; if you're using {{cmd|setupuserpagenumber}}[numberconversion=...] then you'll want to use {{cmd|userpagenumber}} instead.
= Using capitals =
'''Using capitals''' In the previous example, the chapter title and the section title were fetched with the macro <{{cmd>|getmarking</cmd> }} which wraps around <{{cmd>|fetchmark</cmd>}}.
However, in case you need a raw version of the mark, say for instance to put it uppercase, you may use this setup instead:
You can replace <{{cmd>|uppercase</cmd> }} by <{{cmd>|WORD</cmd> }} and so on.
The following file gives a way to achieve marginal and centered headings for doublesided documents. Experiment to achieve other effects!
\startsetups[text a]
\raise\MarginRaise\hbox{\vboxvtop{\hsize=\Margin%
\startalignment[right]
\getmarking[chapter]
\startsetups[text b]
\raise\MarginRaise\hbox{\vboxvtop{\hsize=\Margin%
\startalignment[left]
\getmarking[section]
</texcode>

= Skipping headers or footers =

You can suppress or bypass a header or footer on a chapter page like this:
<texcode>
% with header=high the text area of the page will extend up
% into the space where the header normaly sits

% but does not fill it with any text
</texcode>
Works only if the head title starts a new page. Since section does not do this by default, then you must write
<texcode>
</texcode>

The options for 'header=' and 'footer=' are none,empty,high,nomarking.

= Substituting a shorter lemma for a ''section'' header =

Given a global setup such as

<texcode>
[][section][chapter][]
</texcode>

Sometimes the ''section'' title is too long to fit in the header. Instead of manually inserting a new \setupheadertexts comamnd you may use something like

<texcode>
\startsection
[title={Here is a section title too long to fit in the header},
marking={Here is a section title}]
</texcode>

Similarly, you can send shorter lemmas to the table of contents or to bookmarks. So the relevant keys include

<texcode>
title marking list bookmark
</texcode>