Thanks for posting these Brendan. The combination of White over Yellow flags indicates that the birds were ringed in Hong Kong (note that birds with just Yellow flags are from Australia).
The Curlew is especially interestin - only 2 have been flagged in HK. The fresh flags suggest that this may be a bird ringed earlier this year (March), but it is not possible to know.
We will hopefully start using engraved flags soon, so that individuals will be recognisable. Please continue to look out for these flags, and report them.