I work a lot with documents that use <literallayout
xml:space="preserve" class="normal">, and often these documents have
tabs within the literallayout. The stylesheets handle these correctly and
pass them through to the output document. Unfortunately, these
generally display poorly.
Because different XSL-FO processors treat tabs differently
(FOP treats it as a space and xmlroff treats it as a larger indent), it
would be nice to add a parameter to the stylesheet to specify the size
of the tab in this case.