Has link to a non-HTTP protocol
This means that the URL in question contains at least one outgoing anchor link to a destination URL which uses a non-HTTP protocol (e.g. FTP).
Why is this important?
If you have links with a non-HTTP protocol, there is no guarantee how they would be handled by the user's browser. For example, using the FTP protocol in a HTML link will cause the link to be opened by the users' default FTP client (assuming they have one installed). If there is no distinct FTP client, this might also be the browser. While this is valid, it can lead to unexpected user experiences, as further behaviour is fully dependent on the user's default FTP client.
What does the Hint check?
This Hint will trigger for any internal URL which contains an outgoing anchor link to a URL with a non-HTTP protocol.
Examples that trigger this Hint:
The Hint would trigger for any URL which includes links of the form:
Anchor links to IP address using FTP protocol;
OR anchor links to web address using FTP protocol;
OR anchor links to URL using gopher protocol:
OR anchor links to usenet links:
Why is this Hint marked 'Potential Issue'?
This Hint is a 'Potential Issue', which means that it is unlikely to be affecting the site at the moment, but should be investigated as it could cause issues in the future.
In order to avoid any future issues, we suggest evaluating all instances of links that are using the non-HTTP protocols. The links themselves could easily be a mistake, which would result in a loss of PageRank flowing to relevant pages.
Similarly, if the links are not a mistake, you may still wish to alter the links. For example, if you need to provide a download and have previously been doing this through an FTP link, we suggest that you provide an HTTP/HTTPs download whenever possible, so that the links are within the site are within the control of the webmaster.