because the full english alphabet and the most-used characters in english are included in the seven-bit code points of ascii, which are common to all encodings (even most proprietary encodings), english-language text is less damaged by interpreting it with the wrong encoding, but text in other languages can display as mojibake (complete nonsense). because many internet standards use iso 8859-1, and because microsoft windows (using the code page 1252 superset of iso 8859-1) is the dominant operating system for personal computers today, unannounced use of iso 8859-1 is quite commonplace, and may generally be assumed unless there are indications otherwise.