Attention: The Marketo Community will undergo scheduled maintenance on Tuesday, August 20th between 10-11 PM PDT. During this time, the Community and its content will not be accessible. We apologize for any inconvenience this may cause.
Recommend to look at Marketo's API and to try to follow their naming conventions because the API will be published whether you use it or not. You'll also need to specify an unique API name in all the custom fields. It maybe better to have a naming convention so you'll be able to know which APIs you've created.