NHS numbers and DoB's seen in BMD Index

In Ancestry's beta viewer, NHS numbers and DoB's can be seen in the
margins of certain pages where they are masked on others.

myths...

Which years show DoBs?

Mark...

Try 1976 onward.

John E Wynn...

1976 - 1980 inclusive

John Wynn

I had assumed the Ancestry BMD Index images were of (maybe a stage
removed) of the Registers at the FRC. Are they not?

Could this be a security problem?

Charles Ellson...

Both can be determined directly or indirectly anyway with the
information in a birth register entry. The old identity-card-style of
NHS number has now been superseded by a 16-digit ISO-style number
which IIRC has now no natural link to the birth register entry and
probably does not have any general usefulness should it become known
to others.

nick.cooper-625DETONATOR...

Presumably you mean the old-style alpha-numerical "numbers," that are
no longer valid (everyone has numeral-only ones now)?

Mark...

Oh well, at least some reseachers will save a few bob if needing to just
confirm a DoB.