If you are logged in as an Administrator and visit this link, it will give you a JSON output of all the custom fields (deal, person, and company) and all the dropdown selections available.
For record type specific custom fields:
Search for any help questions or topics.
If you are logged in as an Administrator and visit this link, it will give you a JSON output of all the custom fields (deal, person, and company) and all the dropdown selections available.
For record type specific custom fields: