I saw this in a forum and had to look it up. As hard as it is to believe, the following is true.
Quote: IPv6 Address Nomenclature Used for a UNC Path
Follow these steps when specifying a literal IPv6 address in a UNC path:
Replace any colon ":" characters with a dash "-" character.
Append the text ".ipv6-literal.net" to the IP address.
For example, the nomenclature for a URI that points to a file share on a computer with the IPv6 address 2001:DB8:2a:1005:230:48ff:fe73:989d would be:
\\2001-DB8-2a-1005-230-48ff-fe73-989d.ipv6-literal.net\<sharename> Where <sharename> is the name of the file share on the target computer.