When you book the same room with different points in the same membership, those reservations can be combined into one. It is only when you book them on different memberships...different UY's that it can not and has to be noted.
For example, I own SSR points in both my Aug and Dec UY. If I book RIV on my Aug UY with a combination of SSR and RIV points because I got them at different times, those can be combined into one...
However, if I have to use my SSR points to secure RIV nights on my Dec UY while the other RIV nights were booked on my Aug UY, then it stays two reservations and I have to note it so we don't have to change rooms.