Incorrect warning: "relation identifier contains illegal characters"

[khaliddermoumi]

drafter warns about an "incorrect relation identifier", that is actually correct.

Define a correct relation identifier that is an URL:

+ Relation: http://test.com/order

And drafter will say: "relation identifier contains illegal characters (only lower case letters, numbers, '-' and '.' allowed)" which is wrong, according to RFC 5988, which says that URIs are allowed as a relation identifier.