Special characters in CSS selectors

Question

What is it? Therefore, I can escape from them.

Answer 1

In CSS, identifiers (including element names, classes, and identifiers in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 U + 00A1 and higher, plus a hyphen (-) and underscore (_); they cannot start with a digit or hyphen followed by a digit. Identifiers can also contain escaped characters and any ISO 10646 character as a numeric code (see next element) .code (see next paragraph).

http://www.w3.org/TR/CSS21/syndata.html#characters

Answer 2

- CSS. , CSS (., >, +, ~, #, :, etc) , .

<ns:tagName>, Internet Explorer. , :. , VML , :

v\:* { behavior: url(#default#vml); }