Add the usual "branding DONT's" to the guidelines.

[pablocubico]

Sample from Mozilla.

"For all permitted uses of our trademarks, you may not:
alter our logos in any way
place a logo in such close proximity to other content that it is indistinguishable
make our logo the most distinctive or prominent feature on your website, printed material or other content
use our logos in a way that suggests any type of association or partnership with Mozilla or approval, sponsorship or endorsement by Mozilla (unless allowed via a license from us)
use our logos in a way that is harmful, deceptive, obscene or otherwise objectionable to the average person
use our logos on websites or other places containing content associated with hate speech, pornography, gambling or illegal activities
use our logos to, or in connection with, content that disparages us or sullies our reputation

The logo files containing our trademarks are available under the following copyright licenses: vector logo files under CC-BY 3.0 or later; bitmap logo files under MPL 2."