AS sir george says up to 3mm of water is WET,once you get more you have to look at Contaminated (flood/slush)conditions(A real drag on perf')
Be very careful with SLIPPERY conditions as no authority recognizes these facts for Certification.The crosswind charts for the lowest friction allows one a crosswind of 5knots,and nobody knows the stopping distances.ONe shouldn't be out on a slippery day...If one is on final to a runway reported as POOR braking,you can only enquire as to where the preceding aircraft stopped,or did he go off the end??...Messing around on slippery runways/taxiways ,your on your own!!
I'm surprised there's info in the book referring to 'slippery'.....
