From Edward C. Zimmermann
> There should be a preference for neither. The point of +/- was to avoid
> the discussion.

Yes, I think it is safe to remove BC from the spec altogether and avoid any
further debate over this.  There had been a requirement expressed for BC
dates but since we are expressing the numerical equvalent, I think it is
safe to say that we satisfy that requirement.  I'll simply remove all
references to BC. 

--Ray