If Firefox can't find any encoding declaration in bot HTTP response headers and web page meta tags, and also can't guess, it will use the default encoding. But there are only two choices for default encoding: Unicode and Western, as set apart near the top of the "View | Text Encoding" menu item list. Is it possible to add more choices e.g., Japanese (Shift_JIS)? "Japanese" has always been selected for Auto-Detect. But not much help.