Elements Used in Titles
Elements that can be mixed with the data characters inside the various title elements, for example, inside <title>, <subtitle>, <trans-title>, etc.
Historical Note: In earlier versions of this Tag Set, this parameter entity was used directly with the elements names above. However, in the current Tag Set, unnecessary dependencies have been removed; each element was given its own element-naming parameter entity. In the default case, these call this parameter entity for backward compatibility.
<!ENTITY % title-elements "%simple-phrase; | %break.class;" >
| email | ext-link | uri | inline-supplementary-material | related-article | related-object | bold | fixed-case | italic | monospace | overline | roman | sans-serif | sc | strike | underline | ruby | alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | break