Look in the user's manual at the parts break down.
What nomenclature do they give the part?
On the 1911, the accepted term is slide stop. As a "stop", it should not be used to release the slide.
If the book calls it a release, then release the with it.
(And yes, I know a lot of people use the 1911 slide stop as a release with no ill affects so far, but it is a practice that should be discouraged.)
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)