SCLP
From SnesLab
SCLP on an NTSC console, in region B5 of the jwdonal schematic
SCLP is a solder jumper switch, presumably standing for "solder cut line PAL," which is connected in series with pin 19 of the Video Encoder and ground.
On PAL consoles, this switch is closed. On NTSC, it's open (cut).