CP1252

Windows-1252 or CP-1252 is a character encoding of the Latin alphabet, used by default in the legacy components of Microsoft Windows in English and some other Western languages. It is one version within the group of Windows code pages.

This character encoding is a superset of ISO 8859-1 in terms of printable characters, but differs from the IANA's ISO-8859-1 by using displayable characters rather than control characters in the 80 to 9F (hex) range. Notable additional characters include curly quotation marks and all the printable characters that are in ISO 8859-15 (at different places than ISO 8859-15). It is known to Windows by the code page number 1252, and by the IANA-approved name "windows-1252".

It is very common to mislabel Windows-1252 text with the charset label ISO-8859-1. A common result was that all the quotes and apostrophes (produced by "smart quotes" in word-processing software) were replaced with question marks or boxes on non-Windows operating systems, making text difficult to read. Most modern web browsers and e-mail clients treat the media type charset ISO-8859-1 as Windows-1252 to accommodate such mislabeling. This is now standard behavior in the HTML5 specification, which requires that documents advertised as ISO-8859-1 actually be parsed with the Windows-1252 encoding. As of January 2017^[update], 0.8% of all web sites used Windows-1252, but at the same time 5.4% used ISO 8859-1, which by HTML5 standards should be considered the same encoding, so that 6.2% of web sites effectively used Windows-1252.

Historically, the phrase "ANSI Code Page" (ACP) is used in Windows to refer to various code pages considered as native. The intention was that most of these would be ANSI standards such as ISO-8859-1. Even though Windows-1252 was the first and by far most popular code page named so in Microsoft Windows parlance, the code page has never been an ANSI standard. Microsoft explains, "The term ANSI as used to signify Windows code pages is a historical reference, but is nowadays a misnomer that continues to persist in the Windows community."

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