It means when non-clipped retention is allowed (pretty much the whole fall season), you can tag a total of 10 from the Tillamook District streams (which if my memory serves me correctly, is everything from The North Fork Nehalem on the north, to the Nestucca on the south) for the season. I haven't checked this year (since I'm on the road working, and growing angrier about missing fall fishing by the day), but it's often limited to one non-clipped per day (in addition to a clipped Chinook, coho, or steelhead).