Usage of cell reselection subpriority in LTE

Hi Experts.
Anyone know usage of cell reselection subpriority in LTE.

What is subpriority?
Never heard of.

It’s mentioned in 36.331.
It will add fraction value to absolute prio configured.

I think it’s in NR.
May be in latest release of LTE.

Valid for LTE as well under sib3, 5.
Yes for NR also it’s used.