How to use rules?

[B.Virtanen]

I have one field that should be mandatory in my planning application.
I have tried to make a data validation rule in Contributor Manager but haven't succeed yet.

How can I make a formula that checks is text value filled? I can make rules that compares
number values but I don't have any ideas how to work with text values.

Planning version is 8.3.

[adityashah27]

did you try this?.... item > 0

[B.Virtanen]

Just tried and it worked, thanks!