When using the matching function of ISNA (or any other function), how can I
prevent two identical sets of data on one list from being used to match the
same single identical set of data on another list? I am trying to match one
for one set of data and not use the matched set of data again in any matching
function. For example, if the first list has document A for $100 listed twice
and second list has document A for $100 listed once, I only want one of the
document A for $100 from the first list to match the document A for $100 on
the second list. I want the second document A for $100 on the first list to
not match anything on the second list because the document A for $100 on the
second list has already been used in the matching process.