Check out example codes for "css entities". It will help you in understanding the concepts better.

Code Example 1

/*
!	0021	EXCLAMATION MARK
"	0022	QUOTATION MARK
#	0023	NUMBER SIGN
$	0024	DOLLAR SIGN
%	0025	PERCENT SIGN
&	0026	AMPERSAND
'	0027	APOSTROPHE
(	0028	LEFT PARENTHESIS
)	0029	RIGHT PARENTHESIS
*	002A	ASTERISK


*/


h2:after {
  content: ' \0021'; /* the same as content: ' !'; */
}

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