It should be possible to configure journal pages generation to use either Unicode or HTML date suffixes.
- Unicode: 21ˢᵗ or
- HTML: 21<sup>st</sup>
HTML <SUP> superscripts in Doxygen headings are only rendered correctly when a table of contents is not required, This appears to be a bug in Doxygen. Allowing 'fake' Unicode superscripts would work-around the Doxygen issue.