http://www.poolplayers.com/tmanual.pdf
33. EQUIPMENT
In general, any piece of equipment designed specifically for pocket billiards,
with the exception of jump cues and laser devices, is acceptable in APA
League play. Special equipment, such as bridges and cue extenders, are legal.
Jump shots are legal, when executed properly (see JUMP SHOTS described
in Definitions), but such shots must be attempted using your regular game
cue. Those cues especially designed for jump shots MAY NOT be used in
competition. Players are not allowed to break their cues down to attempt
jump shots.
*Any piece of equipment not covered by this rule and in question will be ruled
upon by APA. Cues with moveable parts will generally NOT be allowed.
JUMP SHOT: A jump shot is when the cue ball is struck with the cue tip in
a downward fashion for the purpose of elevating or jumping the cue ball over
an impeding object ball to achieve a legal hit. It is a foul to jump the cue ball
by “scooping” it over the impeding ball. See a local professional for more
information concerning how to jump the cue ball legally.