What does autoresize = RM+BM mean?
autoresize indicates which bits have been set in the autoresizingMask:
RM = UIAutoresizingFlexibleRightMarginBM = UIAutoresizingFlexibleBottomMargin
The others follow a similar abbreviation syntax.
<SIGMAPOINT_MPAdView: 0x10db888a0; frame = (0 0; 320 50); clipsToBounds = YES; autoresize = LM+RM; layer = <CALayer: 0x282b704c0>>