An associate of mine is designing a historical museum for a small city's
historical society.  The historical society has been collecting objects,
letters,  and photographs for decades, and those artifacts will be exhibited
in the museum as part of  its permanent collection.

The questions are: what is the standard, or appropriate practice when giving
credit to the donors of a museum's collection?   Is everything that is not
public domain given a "courtesy of" line in the text panels?  And how can
they thank donators of period furniture, such as old phones, used as props in
diaramas?

Are there any published guidelines or manuals on this subject?

TIA for your help.  Please reply on or off the list.
Thanks again,
Carmen