Email personalisation

It’s great that Ghost lets us insert Email Content card, and personalise the name of the member in the email they receive.

I want to add some additional personalised fields to my member records in Ghost, and insert those fields into my emails using the same technique.

For example, my service has a unique referral code for every member – I’d like to include that code into my Ghost member records, and then embed Email Content card into my post with a personalised call to action displaying that member’s own unique referral code.

This is basically the same functionality as what already exists with the Hey {first_name, “there”}, Email Content card.

Can this be extended to support additional fields beyond the built-in Name field?