[chef] git resource branch vs revision vs reference

[Jesse Campbell < >]

in the deploy resource, it seems that branch, revision, and reference
are all references to each other.

on one system, I would like to deploy the HEAD revision of the prod branch
on another system, I would like to deploy the HEAD revision of the dev branch
on a third system, I would like to deploy a specific revision
(specified by hash) within the prod branch

I've noticed that if I specify HEAD, it will pull the latest head, but
if I specify prod or dev, it sometimes pulls the latest code, and
sometimes does not.
If I specify the hash, how will I know that it is pulling from the right 
branch?

yay.

in git, branch and revision are wholly different things... is there a
reason the resource treats them identically? how should I be doing
what I want here?

thanks all in advance!