The marathon is limited to 17,500 participants and the time limit is 6 hours.

Although traditionally limited to 250 participants, in recent years it has grown to accommodate expanding numbers.

Trips are one week long and are limited to 12 or fewer participants.

The workshops are limited to 10 participants each, and students may choose to work in black and white, color or both.

Like in-person focus groups, online groups are usually limited to 8-10 participants.

Cornell said seating will be limited to 55 participants, and registrants can send a staff member in their name.

Each of the four sessions is limited to 30 participants (not counting parents), and reservations are required.

Each class, limited to 25 participants, costs $50.

In 2007 the race field was limited to 400 participants to limit the impact on this wilderness area.