what does 'sip' as in 'isSipScala' or 'inSipScala' stand for?

[mtk]

subject says it all.

[SethTisue]

Scala Improvement Process

see https://contributors.scala-lang.org/t/pre-sip-scala-cli-as-new-scala-command/5628
and #559 for context

basically scala-cli includes core commands and more experimental additional commands, and it's an open question if they all remain just thrown together in one bucket, or what