The SBL Handbook of Style, 1st ed., suggests several abbreviations that involve small capital letters (e.g., §8.2).
In the SBL Handbook of Style, 2nd ed., the use of small caps looks to be restricted to Sumerian logograms (§5.5).
Zotero’s rich text markup will support the use of small capitals in a citation’s prefix or suffix fields. Zotero will turn text into small capitals if the text is enclosed by
<span style=”font-variant:small-caps;”> and
</span>. Apparently the simpler
</sc> also works, although the first scheme is preferred.