Add Tax ID Number or allow UDF to be "hidden"

Add Tax ID Number or allow UDF to be "hidden"

I want to be able to add the Tax ID Number of the businesses that we work with, formatted correctly, but still hidden like Social Security Numbers are. I don't want to add a TIN to the SSN portion of a Person card, as that's not an intuitive place for the information to be. But adding a User Defined Field of "TIN" on the Record card leaves the information fully visible. Would love to either have TIN as an available field in the CRM, with the numbers hidden like SSNs or to be able to set a UDF as "hidden," so that the numbers need to be clicked on to be viewed.