cascade and restrict options to alter domain drop constraint

I am puzzled by the cascade and restrict options to the alter domain
drop constraint command.

I do not see how a dropping a check constraint should cascade to
anything, or indeed be restricted by anything.

My reasoning is simple: if I drop a check constraint on a domain, no
data should be affected, so no dependant objects should be affected.

Could someone please explain what I am missing?

Thanks in advance

__
Marc