ICANN has recently allowed for the release of 2 character and ccTLD labels. These names are subject to the 90 day claims provision, even though their TLDs are well past the initial mandatory 90 day period.
The Donuts SRS is able to service claims on a sub-set of the labels in the TMCH, with a specific timeframe just for those names.
If a domain is on the sub-list and a registrar sends a check command, Donuts will return a claims look up key. The registrar must send the matching TCNID along with the create command.
If a domain is not on the sub-list and a registrar sends a check command, we will not return a key, and the registration can proceed without the TCNID.
The .camera TLD had its mandatory claims period from February -April 2014.
Only now is Donuts allowed to sell 2 character labels in .camera.
ap.camera is on the sub-list because it is a 2 character, recently released, that has not yet been subject to claims.
If a registrar sends an avail check, and then requests a look up key, Donuts will respond with a look up key, and require the TCNID to proceed with the registration.
Although it is on the TMCH DNL list, microsoft.camera is not on the claims sublist, because it has already been through claims during the original 90 day period.
If a registrar sends an avail check for microsoft.camera, and then a request for a look up key, Donuts will not respond with a look up key. No TCNID is required to proceed with the registration.
In other words, Registrars may "turn on claims" for the entire TLD but only labels on the sub-list will be subject to claims.