Try this one for starters. (The arcane series of links included typing the word "licence" or even "license" into the Search box on the front page, then clicking the first obscure one that came up).
This argument has annoyed me for ages but I've avoided getting involved. I'll probably regret this.
It's always been clear and plain (to me, at least) that one shouldn't use the Moodle name and trademark to advertise one's Moodle services unless one is a Moodle Partner, since it is these guys who, through their early and/or in-depth commitment to Moodle are approved to supply services. Their solutions are robust and getting Moodle Partnership ain't easy; Mr. D. has high expectations of robustness for technological and business expertise. (Well you would, wouldn't you, if you were letting people use
your trademark to promote their business). They are required to make a (non-trivial) contribution to the Moodle Trust for the privilege of being able to use said trademark. Moodle Partners (generally, as I understand it) largely make their living through Moodle so IMHO they ought to have some sort of security.
Any old Joe can set up a Moodle hosting solution using their favourite shared
hosting provider and sell as many Moodles as they like (until their service grinds to a halt under the load), but a Moodle Partner will give a guaranteed service that is underwritten by the Moodle organisation, or they wouldn't have got Partnership. That's not to say that non-partners can't provide an equally reliable service; they can, but they might choose not to become partners or they might not have made a successful application for whatever reason. The difference is that Partners pay for the right to put "Moodle Services" and the logo on their website and in their advertising. And rightly so.
The difficulty is in the wording I think. Please, somebody (official) tell me if I'm wrong.
"Any Old Joe Moodle Hosting" or "Joe's Moodle Support" would have to be a Partner, since it implies that the services are endorsed by, and specifically for, Moodle.
"Any Old Joe Hosting, which supplies hosting for the Moodle platform" or "Joe's support for Moodle" would not have to be a Partner since the implication is that they are a hosting business that happens to support Moodle. In this case, Joe would not be obliged to support Moodle financially but would not be entitled to use the trademark or logo on his site. He should expect a cease and desist order if he uses it. And it serves him right.
The way I see it,
if through your own vision and expertise you've built a product that many people are prepared and empowered to help develop, such that your reputation is now global and you have a network of organisations who have been bothered to learn and support the product through their own time and expertise AND are prepared to stake their livelihoods on it in sustainable and demonstrably robust businesses AND are prepared to invest
under contract in the aforementioned product,
then you are entitled to put a few restrictions on the use of your trademark, if only to protect the business interests of those people. (If I understand it right, you can restrict your trademark as you like but in Moodle's case it has been done sensitively and appropriately, IMHO).
If somebody doesn't like the restriction they are perfectly at liberty to go away and develop something for themselves, independently. And see if they like it when another party infringes their trademark.
And I agree with HM. Advertising your services in the free support forums unless you're a paying Partner just Doesn't Feel Right.