Unless the RV is branded a "full-time" unit, it should be stored with the slides in and with the weight slightly off the tires and on some material which does not hold water. I use cutting boards, using my jacks to slightly take some of the weight off. Also, cover at least one vent with a Maxi-Cover and leave it open for ventilation.
2013 Rockwood Signature Ultra Lite 8244WS
2015 Ford F250 Quad Cab w/6.2 Engine