Intending to be helpful, some callers routinely say phrases such as
Centers Slip or Centers Slither when they really mean
Slip or Slither, respectively. This can be misleading
because normally the word 'Centers' identifies and activates the Center 4 dancers only.
If the (active) Centers are not in a Wave or other applicable 4-dancer
formation, then they can't do a Slip or Slither. For example,
from Parallel Waves, consider the call Centers Slip: the caller identified
the Centers, who are in a Box; but Slip from a Box makes no sense.
Also, from formations such as Twin Diamonds or a Tidal Wave, Slip
(or Slither) and Centers Slip (or Centers Slither) are