You can use custom objects and fields in HTML templates to display more complex or advanced data in billing documents, including invoices, credit memos, and debit memos.

This tutorial takes invoices as an example; the configuration procedure is similar for credit memos and debit memos.

When using custom objects and fields in HTML templates, keep the following key points in mind:

• Object names must be made plural when they are used in HTML templates. If you define a custom object name as Messages , you have to use default__messageses to refer to the object list. The following table lists more examples.

  API names of custom objects	Names to refer to object lists in HTML templates
  Messages	default__messageses
  Entites	default__entiteses
  Reefer	default__reefers
  ExchangeRate	default__exchangerates
  LegalEntity	default__legalentities

• The custom fields used in a filter must be filterable. For example, if you want to retrieve a list of reefers that belong to a subscription, the custom field SubscriptionName__c contained in {{#default__reefers|FilterByRef(SubscriptionName__c,EQ,SubscriptionNumber)}} must be filterable.