Quick question for Brits about vegetarianism

[Linda C. McCabe]

Do Brits have the term "vegan" in your vocabulary?  Or is this just really a
California thang?

I'm not all that up on the difference between "regular" vegetarians and
vegans other than knowing that vegans are far stricter in what they can
consume.

Just wondering if in a fan fic I can use the term vegan or if I should just
say strict vegetarian.  It's just a small detail.  I don't need any big
explanations as to what is allowed in that dietary regimen.

thanks in advance,
Athena