[1] [DFN[ASCII [RUBYB[大文字・小文字不区別]@en[case‐insensitive]]]]とは、
[[ASCII]] に含まれる[[ラテン文字]]について、それらに限り[[大文字]]と[[小文字]]を区別しないことをいいます。

* 仕様書

-[2] [[Web Applications 1.0]]
-- <http://www.whatwg.org/specs/web-apps/current-work/complete.html#ascii-case-insensitive>

* 仕様書から

>>Comparing two strings in an [DFN[ASCII case-insensitive]] manner means comparing them exactly, code point for code point, except that the characters in the range [CODE(char)[[[U+0041]]]] to [CODE(char)[[[U+005A]]]] (i.e. [CODE(charname)@en[[[LATIN CAPITAL LETTER A]]]] to [CODE(charname)@en[[[LATIN CAPITAL LETTER Z]]]]) and the corresponding characters in the range [CODE(char)[[[U+0061]]]] to [CODE(char)[[[U+007A]]]] (i.e. [CODE(charname)@en[[[LATIN SMALL LETTER A]]]] to [CODE(charname)@en[[[LATIN SMALL LETTER Z]]]]) are considered to also match.

;; [[Web Applications 1.0]] より

* 関連

[3] [[ASCII大文字・小文字不区別]]より大雑把な比較方法として、[[互換性大文字・小文字不区別]]があります。