3.1.1.2.2.4.12 NoCaseString Comparison Rule

This comparison rule is identical to the CaseString comparison rule, except that for each comparison, characters are treated in a case-insensitive fashion. For equality, ordering (greater-than-or-equals and less-than-or-equals), and substrings, two characters are identical if the bytes that represent them are identical or if the characters differ from each other only by their case. The "C" locale, as defined in [ISO/IEC-9899], is used for determining whether two characters differ by case.