The perimeter lines themselves are out-of-bounds.

A disc is out-of-bounds when it first contacts an out-of-bounds area or anything which is out-of-bounds.

For a receiver to be considered in-bounds after gaining possession of the disc, the first point of contact with the ground must be completely in-bounds. If any portion of the first point of contact is out-of-bounds, the player is considered to be out-of-bounds.

If a player makes a catch in-bounds and momentum then carries him/her out-of-bounds, the player is considered in-bounds (to continue play, the player carries the disc to the point where s/he went out-of-bounds and puts the disc into play at that point).

The thrower may pivot in and out-of-bounds, provided that the pivot foot is in-bounds.