We can currently add text options to add to addressee formats. For example "and" or "&".

We are not able to add fields from the actual constituent record. We are limited to the fields given to us on the drop down. These include a few fields on the constituent and spouses record. Occasionally I need to use fields in other parts of the record, especially other additional addressees. For instance I would like to create an addressee format that is [Nametag] and [Spouse Nametag].