From a 61,51 standpoint, it may be logged, as appropriate, as sim time, simulated instrument time, and instructiion received time (you'll find it in the reg).
But since it is never any form of =flight= time, it does not go into an column that reflects flight time. So it's not, for example, PIC time or total flight time.
Because it is not flight time, many pilots (including some who have already posted inthis thread) only list it in its own column, reserving, for example "trainign received" for "=flight= training received" and "simulated instrument" for "simulated instrument in flight." Some also think doing this makes running 8710 totals (which separate flight from sim time) easier.
It's probably more important that you choose a method and use it consistently than which one you choose.