Warn the user that the label has been used before

[Jared12345]

Hi community,

Ive had a request to warn users if they are creating a new record with a similar label, but I am at a loss at how I would achieve this. 

Has anyone done something similar?

[Suvrutt_Gurjar]

Please try in the valid if of the label column

ISBLANK(
FILTER(
"Table Name",
([_THIS] = [Label Column])
)
- LIST([_THISROW])
)

Then you can use a suitable error message such as "This label has been used before." in the valid_if error message field.

Please take a look at the very last section of the article below on avoiding duplicates.

List expressions - AppSheet Help