perhaps, some other big donors. They pledge an amount over a specific period of time. About 20 years ago I knew of 5 who pledged $50k for each of 5 years to go toward the Head Coaches salary (football). This was in addition to what BYU paid.

I'm not sure exactly what it is today, but I suspect there is something similar. I mean there is the CC AD's council that you can join for a $1m or more one time contribution. Last I saw it had double digit membership.