Validation Custom, how to use?

Under Validation Data, there is on the Criteria tab, Allow Custom option, and field to insert Formula.

Does anyone know how to use it?

Any example in use ?

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Help says nothing about it:

Just use any formula that returns a value that maps to FALSE (0) or TRUE (non-0).

Hello @mikekaganski, it is possible to post an example, my attempts nothing happens.

Example of what? E.g., if you are checking validity of cell A1, you could use ISNUMBER(A1). Better tell attempts to do what is failing?

See also Calc: How to specify formula for custom data validity?


Beggining in what LibreOffice version?