B737 Undifferentiated or Other Model
Communication Breakdown; Confusion
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Procedure; Human Factors; Chart Or Publication
On the climb out departing 15L out of IAH we were on the RITAA SID. After checking on with Dept. Control I understood our clearance to be 'climb via the sid; except climb and maintain 16000.' I was confident that is what I heard and I responded with 'climb via sid except climb and maintain 16000.' After discussing it with the Capt I asked and he approved to delete the altitude restrictions at the fix with the 4000B (TTAPS) restriction and the 5000B (BOTLL) restriction. We continued a normal climb to 16000. There was no loss of seperation from other aircraft; no TAs; no RAs and no comments from ATC about our altitude. ATC told us to contact Houston center and we continued a normal flight. After discussing it with the Captain; he and I decided out of an abundance of caution we should file an FSAP in case we misunderstood our climb out clearance. I am confident that is what I heard and what I responded with; but after spending the rest of the flight going over it in my head; I realize that may not have been EXACTLY what the controller said and what I responded with. I just remember reading the clearance back to ATC and thinking 'we can delete those at or below restrictions'; therefore thinking we had received a 'Climb and maintain' clearance.
[Report narrative contained no additonal information].
A B737 flight crew departing IAH on the RITAA RNAV SID off Runway 15 questioned whether ATC's clearance to '...climb via the departure except maintain 16;000 feet' removed the restrictions at or below four and five thousand feet at TTAPS and BOTLL respectively.  They opted to delete the restrictions.