How can I identify an order created via the 'back office'?
Site administration users can create 'back office' orders via /admin -> Store -> Orders -> Create an order.
How can I differentiate orders created this way from orders created by general public users going through the site and placing orders?
For anyone else who is
For anyone else who is interested in this.
I couldn't find any order characteristics that showed how the order had been created. My solution involved modifying one of my custom modules to add another submit handler to the /admin -> Store -> Orders -> 'Create an order' form via hook_form_alter(). The submit handler takes care of recording manually created order ids in a database table.