hi guys n gals just got back from the MOT ...she passed only one advisory ..." vertical play in rear suspension" ... ive rebuilt every thing over winter all bearings / sleeves seemed ok re greased all torqued down when you stand over bike and lift rear wheel up you can feel im guessing a mm of play ? .. thing is ive had other makes of bike which have had this and i recall one bike i had actually had this movement built into the setup can any one shed light on this please ... thanks

 

Guessing your slight knock is bearing related and not a setting preference.
Might be easier to get a mate to assist you finding it. You do the knocking and let him check all the suspension linkages at the same time. Worth a side to side check as well. Swing arm bearings.