I am just throwing this out as remote possibility.   Perhaps this is a mnemonic for Latin use of the word "Who" or "Which"

"Who" or "which" in Latin has the following grammar:

Qui, quae, quod   |    Qui, quae, quae
Cujus                   |    Quorum, quarum, quorum
Cui                      |    Quibums

etc.

See here: Qui, quae, quod.