I have no idea why your text is grey because this is all very good advice. The character class limitations might sound arbitrary but no one who takes this serio

I have no idea why your text is grey because this is all very good advice. The character class limitations might sound arbitrary but no one who takes this seriously is handling Unicode in URLs because there are too many risks. (Not that I’m an authority on the subject but my most regrettable StackOverflow contribution is the regular expression for IRIs which has some flaws and I’ll never revise it because it’s not a good idea.)