May 14 2021 04:59 AM
May 20 2021 05:26 AM
May 20 2021 06:58 AM
It is the Input Message of Data Validation.
Select the cell.
Activate the Data tab of the ribbon,
Click Data Validation in the Data Tools group.
Activate the Input Message tab.
You can remove the data validation rule if you wish by clicking Clear All.