If your matches are anything like mine, any time the ball clips the post or any equipment close to the post, someone inevitably asks the question “Is that a permanent fixture?” To make this rule easy, the answer to that question is pretty much always yes.
The definition of permanent fixtures in tennis include the backstop and sidestops as well as the stands and seats for spectators. Permanent fixtures also includes pretty much all people in the proximity who are not actually playing the match including the spectators, umpires, and ball persons.
To continue my new obsession, the singles sticks and the net outside the singles sticks are also considered to be permanent fixtures. This makes the net an interesting edge case for the permanent fixture rule that only occurs in singles.
This is pretty much the entirety of Section 2 of the Friend at Court. This section merely provides the definition for permanent fixtures. The fact that the point is over when the ball strikes a permanent fixture is a rule for a future day.