The Receipt is a custom activity that gets created when an order is paid. If the receipt if for a meeting registration, dues item, certification application etc. then the activity will be associated with that regarding record. You can locate receipt records by going to the related record and opening the activities or you can do an advanced find for Receipts. These activities are automatically generated when payment is received through any process that accepts payment. An email is also sent via workflow to the customer once this record is created.
Subject -- The name of the record and is automatically generated from the regarding record entity and the date created.
Customers - Provides a link to the account or contact associated with the order.
Regarding - Provides a link to the record associated with the receipt (registration, application, renewal, order, etc)
Priority - Set to Normal by default
Start Date - This field is blank as it is part of a standard activity form.
Due Date - This field is blank as it is part of a standard activity form.
Owner - This will auto populate to your administrator user record since all of these are auto generated by the system.
HTML or PREVIEW - Cobalt Code populates this field with the HTML that will create the email sent to customers pulls from. Note that in the first screenshot you'll actually see the HTML. In Cobalt 3.2+ you will see a preview of the HTML to be received by the customer as seen in the second screenshot.