I remember "Booch Blobs." The original system diagrammer was Grady Booch, and he used these little "clouds." I think Rational Ro$e used them. He ended up throwing in with Ivar Jacobsen, and they came up with UML (which Jacobsen started). More boring, but also more practical.
Jacobson had a proven method and toolset at that time called Objectory which was superior to Rose. Unfortunately they killed the tool. It seems to be an imperative of history that mediocrity prevails better.
I use "pseudo-UML," as a "quick and dirty" diagrammer, but only when I want to do things like this: https://littlegreenviper.com/miscellany/swiftwater/the-curio...
I don't bother with the "official" definitions of UML. I kinda make it up as I go along.