mockingbird = M = mode

mod vt.,n.

[very common] 1. Short for `modify' or `modification'. Very commonly used -- in fact the full terms are considered markers that one is being formal. The plural `mods' is used esp. with reference to bug fixes or minor design changes in hardware or software, most esp. with respect to patch sets or a diff. 2. Short for modulo but used only for its techspeak sense.

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.