> Out of interest, do you know if this holds true for multiplexed tapes,
> i.e. can be read using tar?

Not without preprocessing, AFAIK.  The placement of the multiplex
headers is described in the SAG, but not the layout.  I figured out part
of it a few years ago while working a different issue and have always
assumed I could figure it out well enough to recover data if need be,
given the openness of the rest of the layout from Veritas.  But don't
know it for a fact.  Are you volunteering, Richard?  :-)

If anyone has PD layout documentation, I'd like to see it.