TAPRegExt erratum, Identifiers for Obscore

[Ray Plante]

On Wed, 11 Dec 2013, Mark Allen wrote:
> I wonder how errata would be visible in the ADS linked arXiv REC documents. The ADS
> links are important for visibility of the standards. Perhaps a 'check here for errata'
> link would be needed.

I think this is indeed what is implied by the quoted W3C text: that 
the Rec document contains a URL for where to find an errata document 
(should it exist).  We can place something similar in our boiler plate 
text under "Status of This Document" section.  

cheers,
Ray