Excel Online automatic data fill

Question

I'm working with a file in excel online... I'm not the owner but I want to understand how it works.

There are some cells with no formula where data is automatically filled from others sheets when users type text. How is it possible? If I try to download the file in these cells I can see this formula (in online version there aren't):

=IF.ERROR(@__xludf.DUMMYFUNCTION("""COMPUTED_VALUE""");"ABC")

Probably is set some function that I don't know... Thank you very much for help.

Answer 1

Found it! It was a "QUERY()" function in the first row.