How to unhide a hidden (obsolete) changeset?

[Michael McNeil Forbes]

On Feb 1, 2014, at 5:01 PM, Pierre-Yves David <pierre-yves.david at ens-lyon.org> wrote:

> If you want B to looks like A you could:
> 
> 1) strip any hidden changeset in B `hg strip --hidden 'hidden()'`
> 2) remove all obsolesnce marker in B `mv .hg/store/obstore .hg/store/obstore.foo`
> 3) repull from A `hg pull A`

That is what I was looking for.

Could you point me to the documentation about the format of this file?
(I have a strong and I am sure unadvisable desire to delete portions
of this file to unhide a couple change sets manually.  Is that even
possible?  Playing a bit it sort of seems so, but I expect to shoot
myself in the foot any moment now:-)

Thanks for the quick replies!
Michael.