Boosters and authentic advertising endorsements with private companies are excluded. The problem is that ND does not allow or arrange for rich alumni to directly pay recruits - especially high school recruits. If someone like Sam Hartman is offered an endorsement deal by a shaving blade company, nothing is stopping him from taking it.
But let’s say you are a big fan and you are a multi-millionaire. You hear that ND wants a star QB, DT, or WR, but the amount they are offering from their NIL collective is $250,000. Let’s say Michigan is offering $1 million to the same recruit. You cannot go to ND and say, “Let me make up the difference. I will have my attorney draft a contract to pay the recruit $750,000 pro-rated per every game he plays in his freshman year.” You would be told, “no, you can give to the official ND collective, but you shall not directly contact our recruits, and if you do, you will lose ticket privileges.” In contrast, Texas Tech, USC, Indiana, etc. would welcome the independent offer.
Most rich boosters want to have a say in exactly how their money is spent. They don’t like being told, “just give us the money and ND will decide what to do with it. As usual, ND plays with one arm tied behind its back, just like they always have.