String - Comparison - case-(sensitive|insensitive|less)
Comparing two strings in a case-insensitive manner means comparing them exactly, code point for code point except that the characters in the unicode range U+0041 to U+005A (i.e. LATIN CAPITAL LETTER A to LATIN CAPITAL LETTER Z) and the corresponding characters in the range U+0061 to U+007A (i.e. LATIN SMALL LETTER A to LATIN SMALL LETTER Z) are considered to also match.
Comparing two strings in a compatibility caseless manner means using the Unicode compatibility caseless match operation to compare the two strings, with no language-specific tailoirings. [UNICODE]