Apache httpd officially sets charset of .latin2.html files to
ISO-8859-2 , and so should vim.
au BufNewFile,BufReadPre *.latin2.html :e ++enc=latin2
That is the idea, although I do not know whether it is correct, where
to put it, how to handle file read/write and the like. The same
applies to other supported encodings as well. Also, no idea how to
handle multiple extensions; it seems that httpd actually
prefers .html.latin2 because of MultiViews (selecting candidate
sources on the fly).