Using Salesforce Custom Fields as Tokens

[PROD_-_Deborah_]

For person fields, the tokens are referenced using Lead in front.  For example -   "Lead.First Name". 

For company fields, the tokens are referenced using Company in front.  For example -  "Company.Name". 

For Salesforce custom fields, I'm not sure of the naming convention.  What would replace "Lead" in the "Lead.First Name" token?  I'm trying to use a field called Relationship Manager Email but I'm not sure what the token version would use where the "Lead."  is in the previous example.  Is there a way to determine what the token value would be for a field?

The field is located on the SFDC Custom Field tab.  It is also associated with the Account.

Thanks for your help