While it's true that vegans are also vegetarians going strictly by dictionary definitions, without any other qualifier the term "vegetarian" is usually is taken to mean lacto-ovo vegetarian, at least in some circles.

Whether it's confusing or not or obvious or not, it was an extremely common term in the online vegetarian community I used to participate in around 15 years ago. Not trying to make a judgement on the term, just informing.

"Hackers" have their own version - *nix.