Mechanical bond
forming keys in lath and other materials.
Stucco (cement plaster) around the world:
England:............................Render
Italy:................................Estuco
Spain: .....................Estuco,Revoque
Argentina:..........................Revoque
Central America, South America, Mexico:...repello
American Southwest (Spanish):.......enjarre

Perforated rock lath, also called "button board", had holes punched that allowed mortar to squish through and form keys. This allowed plaster both a suction bond to the gypsum board, but also a mechanical key..
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Keys are formed when mortar is pushed through the lath. Once the mortar sets up, it is locked in place.
More about mechanical bond...
Too much hair spray
causes corruption

Ex-Governor Bob McDonnell of Virginia.

Rod Blagojevich former governor of Illinois.
Maybe it isn't the chemicals in the hair spray, maybe it is the emotional act of putting on the hair spray somehow causes delusions. I may have it backwards- possibly the corruption causes too much hair spray.