I’m awaiting delivery of a FIREWALLA from China.  Along the way the tracking app has been far from useful but it appears the product is finally in the UK!  But then I was faced with “Outward RDC” as a status and had NO IDEA what it meant…

A quick bit of googling and I found this page on the Post office website which seems to cover most things: https://personal.help.royalmail.com/app/answers/detail/a_id/756/