There are some cases need to avoid input error when we collect data when we collaborate with many people. In that case, combox combo box can avoid errors and provide clear direction for every body in the project.
For your information, Data Validation doesn't have an Auto Complete feature, which finds matching items in the list as you start to type. Nevertheless, combo box will be beneficial to avoid errors for collaboration.
Here's steps how to apply data validation to cells
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You can also copy & paste the cell to other cells.
STEP 3) Select "List" on the settings