You can use the Contact Types and Booking Source feature to track the source of bookings and also to allocate a contact to a contact type. For example an agent can be added to a contact type.
On the left-hand menu under Setup, click Contact Types & Booking Source
1. Click on the "Add New Item" link
1.Enter the description for the Contact Type
2. Choose if this is to be added to the "Source of Booking" on the reservation form
3. Make sure you click the active flag.
4. Click "Add Type" to save.