How to define a formula (calc) for: If A1 is exactly found in at least one cell in the range from B1 to B100?

Here is the cell array

(edit: activated screenshot)

Why do you skip first “t” in column A?

Hi JohnSUN, what “Y”?

In your screenshot I see “t” in cells A2 and A4. Second value is striked, but first - in cell A2 - not striked

Ah. OK, forget all t in the first column as I erased this type of entries in the meantime. Sorry for my reading mistake (t as Y) …

Try formula COUNTIF($B$1:$B$100;A1)>0

Thank you. I used it.
And I could act on it successfully for many doubles.

At the end I realized that some doubles are not recognized by the countif … e.g.

Yes, it is possible - this line contains several characters (a dot, a question mark) that have a special meaning in regular expressions. In the Help we can read that “The search supports regular expressions…You can switch the automatic evaluation of the regular expression on and off in Tools - Options - LibreOffice Calc - Calculate.”

Yes, this finds the rest of them. Thank you. :slight_smile: