Suggestion about <- and <= issue

Hi, I feel a bit silly because I just lost a whole chunk of CSS, with no way to get it back, by adding <- in a CSS comment. It stripped all following CSS up to and including the following > (in the line .nav-links > div). That was about 50 lines of CSS later.
I understand this is because of sanitation and I am of course in favor of sanitizing user input, but looking at the forum I am also not the only one who ran into this. So I was wondering if you would consider adding a comment about it under Tips, on the Simple CSS page itself, or if not there, than maybe in the FAQ?