> that model will not satisfy the need to express the fact that
> there are 10 authors; 4 are are from institution B, 3 from institution
> C; author 9 is at institution B and D; author 10 is at instutition D,
> but currently on leave at A; author 10 is deceased. author 7 is the
> corresponding author.

for the revtex model we had each author could have multiple `main'
addresses. In addition any number of `additional' addresses for
`visiting..' or `previously at..' type addresses.

there were also named `collaborations' ie subsets of the author list
grouped in some way orthogonal to address.

Authors may appear all in one list with superscript index to addresses
(which may appear below the author list, or in footnotes, or at the end
of the document, depending on the style) alternatively there may be a
separate author list for each (group of) main addresses.

The hard part is to get an input syntax that can cope with these type of
requirements and at the same time is not impossibly complicated to use
on a simple two-authors-at-one-institution paper.