arrange
Arrangement of Subscripts and Superscripts
Indicates whether multiple subscripts or superscripts applying to the same character should stack (be placed one above the other as compactly as possible) or stagger (be stretched out in a line).
Example
... <p>The <italic>Escherichia coli argU</italic> gene encodes a minor arginine tRNA, tRNA<sup arrange="stack">Arg</sup><sub arrange="stack">UCU</sub>, which corresponds to the rare codon AGA and possibly AGG ...</p> ...