Windows-1251 is a popular 8-bit character encoding, designed to cover languages that use the Cyrillic script such as Russian, Bulgarian, Serbian Cyrillic and other languages. It is the most widely used for encoding the Bulgarian, Serbian and Macedonian languages. 1.8% of all web pages use Windows-1251 in June 2016.
Windows-1251 and KOI8-R (or its Ukrainian variant KOI8-U) are much more commonly used than ISO 8859-5. In modern applications, Unicode is preferred.
Code page layout
The following table shows Windows-1251. Each character is shown with its Unicode equivalent and its decimal code. Legend:
In the table above, 20 is the regular SPACE character, A0 is the NO-BREAK SPACE, and AD is SOFT HYPHEN.
References
Windows-1251 Wikipedia(Text) CC BY-SA