A Meta Field consists of a Meta Key, which defines the property you're defining, and a Meta Value, which is the value of the property. For example, the Meta Key "gs1_template" may have a Meta Value of "Default".
Why would I use them?
You could use Meta Values to store arbitrary data Whiplash doesn't need to ship Orders, but you need on the Packing Slip or some other resource. They can also be used in Search Filters, which can be applied to Rules, Bulk Actions, or reporting.
We don't accept arbitrary Meta Keys. They must first be validated and created by an Admin. Right now, Admins can access Manage → Meta Keys to create and adjust them.
Adding Meta Values to Orders
Meta Values can be added via CSV Order upload or the API.
How can I use them in Templates?
Check out our documentation here.
How can I use them in Search and Rules?
There's a Search Filter for Meta Fields which accepts a Key: Value pair. Regex is not currently accepted, only exact searches.