All ‘real’ butter is dairy based. Might be sheep, goat, camel, buffalo, cow…but it is a product made from one of the mammalian secretions of mammals.

I imagine if you have a dairy allergy it is likely you don’t partake of any dairy products, not just butter.

Peanut butter, almond butter & other nut butters are technically spreads. The conflation caused by using the word butter as a description of consistency instead of the name of a product, adjective versus noun, such as for spreads instead of the word spread, was not as troublesome back when there were more family farms instead of the much fewer factory farms. Butter production was more local then.

Yeah, I am aware of that, have been a reader of ingredients (+ origin) labels since early 80s.. before mass allergies etc was a thing, but what was naturally assumed to be known (common sense) by people bk then i.e 'Dairy' means from cows, is not quite so simple these days... there is vegan 'Butter', it's called Butter and it's in the Dairy Sections with Dairy free cheeses etc. And sadly children (and some adults) who do suffer from allergies and who look at ingredient labels for guidance would benefit from simply stating the fact that 'it does Contain Cows Milk'. that's all I was pointing to.