Click on the cog icon beside the column.
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Select 'Permissions'.
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Deselect the roles, organisations or users that should not be able to view the column beneath the 'View' permission.
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Deselect the roles, organisations or users that should not be able to edit the column beneath the 'Edit' permission.
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Remember to press 'Save' to make any changes live.
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You can also set the same permissions when adding a new free text column.
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