In the course of examining a trademark application, the Examining Attorney may identify issues that preclude registration of your mark. They may be substantive (i.e., there is a fundamental flaw with the trademark you wish to register) or procedural (i.e., there was a problem with your application). Any issues the Examining Attorney identifies will be described in an "Office Action," to which you must respond within six (6) months of receipt.
Some problems raised by an Office Action can be corrected with an "Examiner's Amendment." Essentially, the Examining Attorney will amend the application for you to remove whatever issue was blocking your registration. If Status Code 646 is triggered, it means that the Examining Attorney has amended the application per your request, and is preparing a confirmation to send to you to that effect. No further action is needed on your part at this time. For more information on the Trademark Application Process, visit:
For more information on possible grounds for rejection, visit: