What is Two fragmentations?

In an $\alpha$-cleavage, a bond to the carbon next to a heteroatom or a carbonyl breaks, leaving a cation stabilised by the heteroatom’s lone pair (an acylium ion $\mathrm{R{-}C{\equiv}O^+}$ for a ketone, an iminium ion for an amine). The McLafferty rearrangement of a carbonyl compound transfers a hydrogen from the $\gamma$ carbon to the carbonyl oxygen and breaks the $\alpha$–$\beta$ bond, releasing an alkene and an enol radical cation.