Yep, definitely worthwhile reading the POH - especially the Limitations Section:Also worthwhile noting the placards on the panel.
From the book "Cessna, Wings for the World" by William D Thompson, former Manager of Flight Test and Aerodynamics at Cessna:
"we encountered a nose down pitch in forward slips with the flaps deflected. In some cases it was severe enough to lift the pilot against his seat belt if he was slow in checking the motion. For this reason a caution note was placed in most of the owner's manuals under 'Landings' reading 'Slips should be avoided with flap settings greater than 30 deg due to the downward pitch encountered under certain combinations of airspeed, side-slip angle, and center of gravity loadings.' ... the cause of the pitching motion is the transition of a strong wing downwash over the tail in straight flight to a lessened downwash angle over part of the horizontal tail ... This phenomenon was elusive and sometimes hard to duplicate ... When the larger dorsal fin was adopted in the 1972 C-172L, this sideslip pitch phenomenon was eliminated, but the cautionary placard was retained. In the higher powered C-172P and C-R172 the placard was applicable to a mild pitch 'pumping' motion resulting from a flap outboard-end vortex impingement on the horizontal tail at some combinations of sideslip angle, power, and airspeed."