With all due respect, UA 1K's can pre-book whatever (coach) seat they choose; bulkhead, window, exit row, middle, wing, wheelwell, etc.
To verify this, I just pre-booked (and had confirmed) seat seat 31C (bulkhead) on a 777 IAD-AMS for an upcoming trip (but expect to be upgraded to C using a 1K Systemwide Upgrade.)
Edit: and yes, row 16/17 is a bulkhead not an exit row.)
[This message has been edited by transpac (edited 08-22-2000).]