The following spreadsheet describes the available mappings, code used, fields that work or don't work and those that will be removed and those that will be fixed.
To create templates use Adobe Acrobat DC. Start with a pdf form and add fields using the Data Placeholders noted in the spreadsheet above. You can also download a template from the Invoice Templates lookup to see an example.
Once you have your template created, create a new Invoice Template.
Identify the Organization that is associated with this template, you can restrict who can edit different templates based on their organization.
Enter an invoice template code and description. Check the Restrict Use by Chart/Org if you want to restrict use of the invoice template by AR billing chart/org.
After you have created your template, use the lookup to upload the invoice template. Note there are a few templates on the following screenshot that don't have any actions because their templates have been restricted from use.