http://vim.wikia.com/wiki/File_format

:e ++ff=dos

set ffs=dos
set ff=dos

# ffs - fileformats, ff=fileformat

https://vim.fandom.com/wiki/Working_with_Unicode

:h utf8
http://vimdoc.sourceforge.net/htmldoc/mbyte.html#utf8
    set encoding=utf-8
http://vimdoc.sourceforge.net/htmldoc/options.html#'bomb'
    set bomb