IE users can add UNC paths in linked documents and open the file; however, it requires changed Internet Option settings. This applies only to IE. Most other browsers do not allow users to click the link and open the file. Use of the UNC path is for information only in those browsers.
If you use UNC paths as linked documents, the WebTMA Server must be added as a trusted site in IE. This can be pushed as a group policy setting by a Network Administrator at the client site or set manually through the Security Tab of the Internet Options window illustrated in the screenshots below. For an article from Microsoft (as of June, 2016) regarding these settings, go to https://support.microsoft.com/en-us/kb/815141.
The Require server verification (https:) for all sites in this zone check box is marked by default. Clear the check box to allow sites to be added that do not include the HTTPS protocol.