I did a search for tags with the namespace "dc:"
See
http://api.flickr.com/services/rest/?method=flickr.photos.search&api_key=744dbdd\
f5c50c0176befdcae9d095a57&machine_tags=dc%3A&extras=machine_tags
or (the equivalent):
http://tinyurl.com/2uddvn
The search brings back a number of photos that have empty machine_tags
attribute in photo. For instance, look at
http://flickr.com/photos/65121277@N00/362618347/
-- the "dc" namespace is not being used, but "dc" is being used as a
predicate (i.e., xmlns:dc=http://purl.org/dc/elements/1.1/)
Is this a bug or expected behavior?
-Raymond