User JellicleCat posted this on linguistics stackexhange a few years ago. None of us were able to come up with a satisfying answer but most seemed to agree that it was an idiosyncratic cipher or shorthand. It means that puzzlers may be better equipped to solve it than linguists.
Anyway, the original question was:
I've wondered about this script since I saw it years ago. I imagine it's an English cipher. Can anyone tell me?
He later added in the comments section:
an intern left it on his notepad on his last day in the office