I suppose that mac_centeuro can be removed since it is identical to mac_latin2, and there are already some aliases for mac_latin2. Then, mac_centeuro can be added as an alias for mac_latin2.

I'm not sure about why latin_1 and iso8859_1 are both supported (they are identical). The doc says:

 "CPython implementation detail: Some common encodings can bypass the codecs lookup machinery to improve performance. These optimization opportunities are only recognized by CPython for a limited set of (case insensitive) aliases: utf-8, utf8, latin-1, latin1, iso-8859-1, iso8859-1, mbcs (Windows only), ascii, us-ascii, utf-16, utf16, utf-32, utf32, and the same using underscores instead of dashes. Using alternative aliases for these encodings may result in slower execution."

Also not sure whether this would matter or not.