From Rob Lewis, 2 pics of a wing-tagged female marsh harrier - orange tags on both wings, the nearer tag reads.....IL?
Orange wing tags look as if they might belong to the NW Norfolk Ringing Group, orange being their colour from June 2018, I've notified Phil the project coordinator.
http://www.nwnrg.co.uk/research/marsh_harrier/tag.htm
Plus 2 buzzard, 1 ♂ merlin dashed past the hide, 1 sparrowhawk,