Yes they are.
Only in long track. In short track they are prohibited.
Suck my balls
Yes, Slazenger still produces tennis balls. The brand is known for its long-standing history in the sport and continues to manufacture a variety of tennis products, including tennis balls used in professional and recreational play. Their balls are often recognized for their quality and are used in various tournaments.
The track ball is the ball on the underside of many older mice, used to move the cursor about the screen. The DPI on these is very poor compared to laser & optical mice, and you sometimes have to deal with people removing the track balls.
Each ball will have a stamp that says what game it was played in and who played as well.
Multi-track analog tape recording is still used today (although not commonly).
you mum suck balls
There are still leather balls used in rugby matches.
My balls
Well track balls would be better do to being able to use it on any surface
Pearl. Here is a URL to the specifications for the ball. http://www.bowlersparadise.com/shop/balls/track/track_505a.shtml
It was an airfield. There is also still a farm on the infield.