A "stickler" is someone who is very strict and precise about following rules or standards, and they don't tolerate any deviation from them. Full definition
Good for: People who aren't sticklers for details and who want a Watch app. (policygenius.com)
And you witness dramas about getting attribution probabilities right — for example, the American Physical Society statement on climate change, which has a few of their members foaming — and you realize that the scientific community is full of sticklers about getting the uncertainties right (as they should). (dotearth.blogs.nytimes.com)
You could use some homemade or store - bought vegan mozzarella if you're a real stickler when it comes to French onion soup - themed things, but honestly, the spreadable cheese is delicious and it really does taste French onioney when paired up with the burger and caramelized onions, so you should make it. (connoisseurusveg.com)