Anyone can help me with IRCTC questions? (Traveling from Jaipur to Jamnagar) | Tried IRCTC helpline but that didn't solve my queries well.

I just booked my ticket from Jaipur to Jamnagar and it's showing (booking = PQWL/172) (Current = PQWL/98) what does it mean? and while booking a waiting ticket should we choose something in seat preference option? or leave it as No preference?