While we're here, does anyone know if a sole proprietorship donating to OS projects for "sponsorship" (aka listing the donor company's name in the project's github) is deductible as Advertising expenses? Specifically wondering about Canada personally, but I'm sure people in the U.S. would benefit from this knowledge as well. Our tax law (in Canada) is so opaque, and I feel like finding ways for these monetary contrib…
Talk to an accountant. As I understand it, in the USA, "donations" are not deductible unless they are to a bona-fide charity/501(c)(3) type of organiztion. To be deductible as advertising, I would think the payment would need to be be explicitly for advertising services, not a dontation with the side-effect that you are recognized and thanked on a list of donors. That's just a courtesy, not an advertisement.
I can't imagine this is too different from paying a youtube or social media influencer to promote your product, or paying for an ad spot on a podcast.