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SharePoint Custom Mask & Unique Field Validation

General Mask Settings

Enter the description for new mask, mark the mask as required or not.

Then define unique scope (current list, current site or current site collection).

*Note: you can set unique scope later on as it is described in previous section. *

Now define field case – the way text will be displayed: Capital, UPPER or lower.

Then select a separator you want to use.