By the way, "SP" stands for Suppressive Person

Like most of the made-up words that a "certain religion" uses in order to keep the general public from understanding what's going on, SP is rather cryptic, but essentially it's someone who has been officially cast out of the Church.

Here's an example of someone's SP Declare, a document officially expelling them: http://www.holysmoke.org/cos/sp-declare-swazey.htm