How to make font of a comments big?

How to make font size of a comment big? What’s the markup?

Can all users do it? Or, only selected guys have this privilege? @DVK in question is topmost guy on SFF.SE and has Gold Badge in harry-potter tag. Has something to do with that? also i want to write comment in desiging font style from Anchor fonts can i do this if anyone knows about this please tell me

I don’t think you can set a personal font but you can still use markdown headings when you need to handle the font size in titles: