The following image shows the Manage Custom Fields page.
Custom fields are a powerful to add extra data to cards that are sent. For example, you can ask the sender to set their location. You can then add this data anywhere you like in the card.
To add a new custom field firstly give it a name and a unique identifier. The identifier should be short and not contain any special charatcers or spaces. You can also choose whether the field is comulsory or optional.
At the bottom of the page you can edit or remove exisiting custom fields.