4 · Society, Civilization, Culture
43 · recreation, amusement
43C · sports, games and physical performances
43C4 · games of skill
43C41 · ball games
43C415 · ball games in which ball is hit with racket (or hand)
43C4151 · tennis, lawn-tennis
43C4151(+4) · tennis, lawn-tennis (+ requirements, necessaries ~ sports and games)
43C4151(+41) ·
tennis, lawn-tennis (+ equipment, outfit (sports, games, etc.))