I live near a school, so they have these painted on the road near the “suggested safe path to school”. But given that I don’t have a kid myself (THAT I KNOW ABOUT, RIGHT LADS? OOERR MISSUS), so I have no idea what “SLLT” stands for.
The best I can come up with is “Stop, Look, Listen, Take drugs” (keep in mind that I live in Brunswick, so that could really bit what it means)