Ringed Crow

Using Google I found that the British Bird Council issue numbered close rings to be fitted on captive bred birds - unfortunately I can't find details of a ring issue register.  I think Social Media may be the best option but I avoid it like the plague!

Thank you very much for your opinion, Stuart. Which leads me to my next question - if privately bred birds have to be ringed by law, is there a register of some sort whereby a ring number/species can be traced, similar to the pigeon ringing system?
My thoughts now are that this bird is relatively local, the breeder may be on social media, but I’m not on social media, so investigation in this direction is not possible. If any member is interested in this sighting and are on social media I would be grateful for any assistance. 
Thank you, Stuart, for your help.

The characters you have recorded are definitely not from a BTO or foreign ringing scheme.  People who breed native birds in captivity are obliged by law to fit closed rings on them.  I can only assume that this Crow has escaped from a private collection - I have been unable to trace the ring number on Google.

Ringed Crow has revisited this afternoon, again with three others, have managed to view some characters on the ring, but difficult as bird was continually walking about.

The ring at closer inspection looks quiet new, the visible characters appeared to be - 124 AG  LWR -    Other characters are there but not visible as on inside leg of the ring. Bird here for approx two minutes before being disturbed, pity.  Characters are black on what looks more like brass or copper.

Sorry I couldn’t get more, but the visit shows it’s still around, so maybe next time.

ThankYou for the info, Stuart. I’ll keep a closer look out to see it reappears and get a better look, also see the ring again.. A first impression was that this was a young bird. 
Thank again

This does not sound like a bird ringed by BTO ringers.  Last year no Crows were ringed anywhere in Lincolnshire.  A single yellow ring sounds like a bird that has been kept in captivity and may have escaped - sorry I can't be more helpful.