What does skl stand for?

Excuse me, could you clarify something for me? I've been hearing this abbreviation 'skl' quite frequently in the cryptocurrency and finance circles, but I'm not entirely sure what it stands for. I've done some searching but haven't been able to find a clear definition. Could you possibly enlighten me on the meaning of 'skl' in this context? It seems to be a term that's gaining some popularity, so I'd really appreciate if you could provide a brief yet precise description of what it signifies in the world of cryptocurrency and finance. Thank you for your time and assistance.