MANUAL: more detail on customization in syntax highlighting section.

MANUAL.txt

@@ -4624,9 +4624,9 @@ Syntax highlighting
 
 Pandoc will automatically highlight syntax in [fenced code blocks] that
 are marked with a language name.  The Haskell library [skylighting] is
-used for highlighting, which works in HTML, Docx, Ms, and LaTeX/PDF output.
-To see a list of language names that pandoc will recognize, type
-`pandoc --list-highlight-languages`.
+used for highlighting. Currently highlighting is supported only for
+HTML, EPUB, Docx, Ms, and LaTeX/PDF output. To see a list of language names
+that pandoc will recognize, type `pandoc --list-highlight-languages`.
 
 The color scheme can be selected using the `--highlight-style` option.
 The default color scheme is `pygments`, which imitates the default color
@@ -4634,6 +4634,24 @@ scheme used by the Python library pygments (though pygments is not actually
 used to do the highlighting).  To see a list of highlight styles,
 type `pandoc --list-highlight-styles`.
 
+If you are not satisfied with the predefined styles, you can
+use `--print-highlight-style` to generate a JSON `.theme` file which
+can be modified and used as the argument to `--highlight-style`. To
+get a JSON version of the `pygments` style, for example:
+
+    pandoc --print-highlight-style pygments > my.theme
+
+Then edit `my.theme` and use it like this:
+
+    pandoc --highlight-style my.theme
+
+If you are not satisfied with the built-in highlighting, or you
+want highlight a language that isn't supported, you can use the
+`--syntax-definition` option to load a [KDE-style XML syntax definition
+file](https://docs.kde.org/stable5/en/applications/katepart/highlight.html).
+Before writing your own, have a look at KDE's [repository of syntax
+definitions](https://github.com/KDE/syntax-highlighting/tree/master/data/syntax).
+
 To disable highlighting, use the `--no-highlight` option.
 
 [skylighting]: https://github.com/jgm/skylighting