To reduce sail area by rolling or folding part of the cloth – usually along the foot in mainsails and along the luff in headsails, though either form is found in either sail. The process of making a reef is commonly called ‘tucking-in a reef, even where roller-reefing is used and there is no actual tucking. The reverse procedure is ‘shaking out a reef, an expression that suits a condition where cloth has been bundled and crumpled up. A reef is in fact that area of a sail between the foot and a set of reef points, or between two sets of reef points. Hence the expression to ‘take in a reef. In times past the lowest reef was sometimes called the ‘slab’ and this term has been revived for the folding type of reef, where a pre-determined area of cloth is taken in (ie. jiffy and points). The Slab reef contrasts with the rolled reef where the amount of cloth accommodated on the boom is continuously variable and not in discreet steps. All types of slab reef make use of Cringles (eyes) on the luff and leech of the sail, and these are first hauled down to form the new tack and clew of the sail. It is then necessary to tidy up the excess cloth along the foot of the sail, which is known as the Bunt. Whether or not there is a boom, the bunt can be firmly held by short lengths of cord, called Pennants or Points, which pass through eyelets in the sail cloth. Alternatively, but no so conveniently a continuous length of line may be threaded through the eyelets and around the bunt. The modern jiffy reefing for boomed mainsails makes use of elastic cord, a length of which is permanently threaded through the reef eyelets from luff to leech. After the tack and clew cringles have been hauled down to the boom, bights of the shock cord are stretched down and tucked under hooks on each side of the boom.