I've recently found a poem on some YouTube videos pertaining to Orbital Drop Shock Troopers, most notably on an extended and edited version of Light of Aidan's Lament (the song used in the live-action trailer for Halo 3: ODST). The poem goes as follows:

"Blood is red, our armor is black.

Kill us and kill us but we'll just come back.

Raid our bases, you might just get by;

But before you know it we'll come from the sky."

This poem isn't mentioned anywhere else in Halo canon, so what I'm wondering is if this is a fan-created poem, or if it is actual Halo canon.