Optional Boolean. If TRUE, the field is not displayed in New or Edit forms but can be included in views. In addition, setting ...

Optional Boolean. If TRUE, the field is not displayed in New or Edit forms but can be included in views. In addition, setting ReadOnly to TRUE hides the field from Site Settings pages for managing site columns and content types. Setting the Hidden attribute to TRUE completely hides the field from the UI. If you do not include this attribute, SharePoint Foundation treats the column as if this attribute is set to False.