jargon.artrocity.com
New Hacker's Dictionary the Jargon File v 4.4.6
[by analogy with ‘append’] To prefix. As with ‘append’ (but not ‘prefix’ or ‘suffix’ as a verb), the direct object is always the thing being added and not the original word (or character string, or whatever). “If you prepend a semicolon to the line, the translation routine will pass it through unaltered.”