RAW
From NMR Wiki
Acronym RAW stands for randomization approach for water suppression[1].
RAW element consists of a selective 90o pulse on solvent resonance, followed by a strong PFG along z axis. The selective rf pulse tips magnetization of solvent (water) resonance to transverse plane, and the field gradient dephases the magnetization.
This technique improves water suppression in the experiments using non-excitation readout techniques (e.g. watergate, water flip-back).