A
polo shirt and a pair of slacks qualify as golf apparel, mostly
because golf is a low-intensity sport. Compared to basketball and
baseball, golf doesn't require rigorous physical activity other than
swinging the club. You may break a sweat during a game from the heat
or from intense mental concentration, but not necessarily through
physical exertion.
The
only thing that limits your choice of golf apparel is the dress code.
During the early 1900s, country clubs were very particular about
proper dress code for guests and members. Knickers, for example, were
prevalent at golf courses at the time but were shunned by country
clubs. These places obliged players and spectators to come in more
formal wear, particularly the collared shirt.
