Originally Posted by
john_tullamarine
The aim is to arrive at the final clean speed as the flap finally retracts. The requirement is not worse than level flight but how to do it best for a given aircraft will be prescribed in the AFM.
While deferring to Centaurus (who has about a gazillion times more 737 experience than I), I seem to recall that the idea with the 737 was a shallow climb to avoid over running the clean speed during the retraction sequence.