I'm working my way through that (rather long) article now. I can already see one improvement in future lookups. One problem with VLOOKUP is that the target column must be to the right of the index column; wherever that's not the case, I used to use MATCH with INDIRECT to construct a pointer to the desired value. I recently realized that OFFSET is better than INDIRECT. But INDEX: is better yet. I'll keep reading.

Oh, and by the way, I never knew about the IFERROR function. That's marvelous!