I use the words ‘dominance’ and ‘defense’ to describe being on the top and bottom of cross-sides, knee-mount, mount, and back respectively. Such langauge isn’t quite 100% because there is structural interchange happening in every moment.
In other words, you have to account for everything at all times. Just because I get passed your legs doesn’t mean I don’t need to stop tracking what your arms are doing. To the contrary:
While some may write off such technique, I believe it’s going to become increasingly prevalent as BJJ evolves. You have to be willing to learn everything.