[Antonella]

Rule 1 - Sec. 15. CATCH.
A catch is a legally caught ball, which occurs when the fielder catches a batted or thrown ball with his hand(s) or glove.
A. (...)
B.(...)
C. The fielder’s feet must be:
1) When moving toward the out-of-play line, the feet must either: (a) be within the playing area, (b) touching the ‘out-of-play’ line or(c) both feet in the air after leaving the playing area, in order to have a valid catch.
2) A player, who is in dead ball territory and returns to the playing area, must have both feet touching the playable area. In order to have a legally caught ball.