Identifier field

Hello all,

I wonder if the identifier should be different from @id. I am in support 
of havng the @id be the identifiers.org URL (with namespace use) e.g.

"@id": "http://identifiers.org/pdb:4wa9"

And the identifier by the dataset specific identifier for the resource 
being marked up, instead of the same identifiers.org URL e.g

"identifier": "4wa9"

REF: https://www.w3.org/TR/2014/REC-json-ld-20140116/#node-identifiers

Thanks,

-- 
Stephen Anyango
PDBe
EMBL-EBI