One cell in the table header, as opposed to an ordinary cell in the body of a table. (This element is based on and intended to be converted easily to the XHMTL th element.)
Any combination of:
Text, numbers, or special characters
Linking Elements
<inline-supplementary-material> Inline Supplementary Material Metadata
Related Material Elements
Emphasis Elements
Inline Display Elements
Math Elements
Other Inline Elements
Baseline Change Elements
Citation Elements
Lists