How to enter a lead with only a phone number?

How to enter a lead with only a phone number?

Zoho is my first attempt at some sort of lead tracking tool.  I am a real estate investor and often my leads begin with nothing more than a phone number from a yard sign and/or an address.  First off, is this the right tool for this?
 
Next, if it is, how do I enter a lead when a phone numbers is the only information I have?  The form seems to require NAME. Could I enter FSBO or something similar as the name?
 
Any suggestions on how to make this tool work best for me are appreciated.
 
 
Thanks,
Bob