regex to allow special characters code example

Example 1: regex allow alphanumeric and special characters

/^[ A-Za-z0-9_@./#&+-]*$/

Example 2: regex match numbers and special characters

echo %H1E2L+L#O! | sed 's/[^A-Z!]//g'	#replaces number and special
characters which aren't ! or an uppercase letter A-Z