Another issue I have run into is recursion, when a reference includes
another reference. This comes up in various forms:
Also published as ...
Errata available at ...
Summarized [or reviewed] in ...
Preprint available at ...
Often such a reference takes the form of a URL or a page in a journal
or in a proceedings. This can be most succinctly placed in situ --
formatted consistently with other references. If the reference
identifies an alternate mode of publication, it may lack %A or %T
fields.
Partial proposal. a %O field may contain a reference, with no further
recursion, The contained reference will be formatted in line in the %O
text unless references are accumulated and the contained reference is
not unique.
Doug