Quote from the Official Standard (New amendment in red)

"Moderate in length, (*) very thick, deep and strong.  Well-arched at back, with much loose, thick and wrinkled skin about the throat, forming dewlap on each side, from lower jaw to chest."

(*) - removed 'rather short than long'.

Well-arched neck with much loose,  wrinkled skin. 

"Moderate in length (rather short than long), very thick, deep, strong."