At minimum, CUI markings for unclassified DoD documents will include the acronym “CUI” in the banner and footer of the document. If portion markings are selected, then all document subjects and titles, as well as individual sections, parts, paragraphs, or similar portions of a CUI document known to contain CUI, will be portion marked with “(CUI).” Use of the unclassified marking “(U)” as a portion marking for unclassified information within CUI documents or materials is required.