ismark

Determines whether a character is a mark (non-spacing mark, combining mark, or enclosing mark in Unicode speak).

Given some UTF-8 text, obtain a character value with utf8_get_char.

Note: in most cases where isalpha characters are allowed, ismark characters should be allowed to as they are essential for writing most European languages as well as many non-Latin scripts.

Parameters:

c	a Unicode character

Returns:

true if c is a mark character