Looks like @Belmont is right.
This is the response I got from the USEF.
In response to your email, the Federation does not recommend that amateurs participate in ambassadorship programs as they often mirror the Federation’s rules on sponsorships. The relevant rules have been copied below.
Chapter 13, GR1306.2
2. Remuneration. Remuneration is defined as compensation or payment in any form such as cash, goods, sponsorships, discounts or services; reimbursement of any expenses; trade or in-kind exchange of goods or services such as board or training.
Chapter 13, GR1306.4d and l
4. Professional based on one’s own activities. Unless expressly permitted above, a person is a professional if after his 18th birthday he does any of the following:
d. Accepts remuneration AND uses his name, photograph or other form of personal association as a horseperson in connection with any advertisement or product/service for sale, including but not limited to apparel, equipment or property.
l. Accepts remuneration for such use AND uses commercial logoed items while on competition grounds unless expressly permitted by applicable division rules
The barn that an amateur rides at can be sponsored, however, the amateurs must be very cognizant of not receiving any of the products or services that come with the barn’s sponsorship. For example, if the barn is sponsored by a feed company, the amateur’s horse cannot receive the sponsored/discounted/gifted feed, and they must pay for their own feed. The same applies to any tack, equipment, apparel, etc, type of sponsorship. We normally recommend that amateurs not be a part of farms that are regularly sponsored because these types of arrangements make it hard to separate the sponsored horses/riders versus the amateur-owned, non-sponsored horses/riders.
I can totally relate to your frustration @mvp (Also, to answer your previous question I ride/lesson at the barn - not train or pay others to train the horses). It’s clear that this other ammy rider I mentioned before is obviously breaking the rules. Soooo… there’s that. Not a whole lot to do about it but at least I know I’ll be above board. Bummed out though, I had an opportunity for a lovely little sponsorship from a company I LOVE.
I don’t know if I necessarily agree with the ammy’s not being allowed to be sponsored (read: helped with inherently expensive horse needs) - anyone able to explain the reasoning behind that? Maybe I’m missing something. I reckon it probably would just descend into total sponsorship chaos. Alas, rules are rules!
At any rate, I hope this response from the USEF helps clarify things for anyone else wondering about the issue!