Message

Unregistered link relationship: foo

Explanation

The current values for the Registry of Atom Link Relations are as follows:

Solution

Change the attribute value to one in the list.

If a value other than one of the above is desired, either register the relation with the IANA registry, or express the rel as a fully qualified URI.

Not clear? Disagree?

You might be able to find help in one of these fine resources.