On what pages are default value and validation rules supported?

You can configure default values and validation rules only on these fields:

Property name Property label Type Entity GUI
Account Number customer_number field activity text
Activity Type aworktype field activity combobox
Address caddress field activity text
Appointment Number appt_number field activity text
City ccity field activity text
Customer Email cemail field activity email
Customer Mobile Number ccell field activity phone
Customer Phone Number cphone field activity phone
Duration length field activity text
Time Slot time_slot field activity text
Inventory Type invtype field inventory combobox
Name cname field activity text
Points apoints field activity text
Quantity quantity field inventory text
Serial Number invsn field inventory text
Service Request Type srtype field service request combobox
State cstate field activity text
ZIP/Postal Code czip field activity text