I don't know what type of 'ink' they use to mark the lumber but you might find the stamp is gone after a heavy rain.
No matter, a power washing will remove the stamp. Also, if you use a bleach-based deck cleaner, it too, will remove the stamp. The thing is that if you use either method, you ought to do the entire deck. Otherwise, you'll see really cleaned ends and relatively clean deck boards.
If you use the latter method, make sure you read the container. There are 'side effects' on shrubbery. If you want to wait until next Spring or Summer, that would give the wood time to 'settle' in its own special way, and it will be ready for a cleaning and sealing by then. My best to ya and hope this helps.