Very good question.
An undocumented feature in Microsoft Excel
The official help page in Excel in
indicates this under the criteria for the field Tree in the example
="=Apple"
If you enter in cell A3 the formula ="=A", visible as =A after the formula is entered, you will get the correct results
And if you enter ="=A*" you get the same result as just entering the value A.
That means any text is interpreted as ="=<text>*"
As a wildcard you can also list the values with A and any -but only one- character by using ="=A?"
Or anything ending in A, ="=*A" .
The second = is important. If missed there is no error, just incorrect results. Try ="*A"
Regards,