Question: Sliding shoes are worn by curlers during what activity?
About the article "Curling", section "Shoes".

Candidate passages:
Curling shoes are similar to ordinary athletic shoes except that they have dissimilar soles; the "slider shoe" is designed for the off foot (or sliding foot) and the "non-sliding shoe" for the hack foot.
The "slider shoe" is designed to slide and typically has a Teflon sole.
It is worn by the thrower during delivery from the hack and by sweepers or the skip to glide down the ice when sweeping or otherwise traveling down the sheet quickly.
Stainless steel was once common for slider soles, and "red brick" sliders with lateral blocks of PVC on the sole are also available.
Most shoes have a full-sole sliding surface, but some shoes have a sliding surface covering only the outline of the shoe and other enhancements with the full-sole slider.
Some shoes have small disc sliders covering the front and heel portions or only the front portion of the foot, which allow more flexibility in the sliding foot for curlers playing with tuck deliveries.
When a player is not throwing, the player's slider shoe can be temporarily rendered non-slippery by using a slip-on gripper.
Ordinary athletic shoes may be converted to sliders by using a step-on or slip-on Teflon slider or by applying electrical or gaffer tape directly to the sole or over a piece of cardboard.
This arrangement often suits casual or beginning players.
The "non-sliding shoe", or "hack foot shoe," is worn by the thrower on the hack foot during delivery and is designed to grip.
It may have a normal athletic shoe sole or a special layer of rubbery material applied to the sole of a thickness to match the sliding shoe.
The toe of the hack foot shoe may also have a rubberised coating on the top surface or a flap that hangs over the toe to reduce wear on the top of the shoe as it drags on the ice behind the thrower.
High heels are often worn by women as dress shoes for special occasions. 
  Shoes must be worn at all times.
Footwear must be appropriate for the student’s designated activity.
Slippers are not permitted.  
Although high-heeled shoes or boots have more often been worn by women, in various times and places they have been standard features of men's footwear too, either for practical reasons or as fashionable items.
Mongolian horsemen were among the first to use heels as means to keep their feet from sliding out of their stirrups.
It is also well known that Egyptian butchers wore high heels so they would not step directly in offal.
Pharaohs and nobles in Ancient Egypt would wear high heels to show power and for ceremonial purposes.
Actors playing tragic roles in ancient Greek drama wore the buskin, a boot with a platform sole, designed to give them greater height over other actors.
The Romans, both men and women, wore cothurns, or sandals with platform heels; these were intended to lift the wearers above mud and garbage in the streets.
Geta, which are based on a similar concept, are still used in Japan today.
American cowboy boots, first developed in the 19th century and still popular today in some parts of the United States, have high underslung heels to keep a rider's foot from sliding through the stirrup.
High-heeled platform shoes were a widely popular form of men's footwear during the 1970s. 
Organ shoes are shoes worn by organists, designed to facilitate playing of the organ pedal keyboard.
Also, since organ shoes are worn only at the organ, the use of special footwear avoids picking up grit or grime that could scar or stain the pedal keys.