Some countries or languages show a higher usage than the global average, in 2024 Brazil according to website use, use is at 2.9%,[7] and in Germany at 2.5%[8][9] (these are the sums of ISO-8859-1 and CP-1252 declarations).

[16] Starting in the 1990s, many Microsoft products that could produce HTML included Windows-1252-exclusive characters, but marked the encoding as ISO-8859-1, ASCII, or undeclared.

[citation needed] Characters exclusive to Windows-1252 would render incorrectly on non-Windows operating systems (often as question marks).

[17][18] In particular, typographers' quotes—curly variants of the standard straight apostrophes and quotation marks in US-ASCII—were commonly used in files produced in Windows applications such as Microsoft Word due to the smart quotes feature, which can automatically convert straight apostrophes and quotation marks to the curly variants.

[19] To fix this, by 2000 most web browsers and e-mail clients treated the charsets ISO-8859-1 and US-ASCII as Windows-1252[citation needed]—this behavior is now required by the HTML5 specification.

According to the information on Microsoft's and the Unicode Consortium's websites, positions 81, 8D, 8F, 90, and 9D are unused; however, the Windows API MultiByteToWideChar maps these to the corresponding C1 control codes.