Final answer:
The statement is true; documents designated with Controlled Unclassified Information (CUI) must have the acronym "CUI" or the word "controlled" marked at the top and bottom of each page.
Step-by-step explanation:
The statement about CUI markings on unclassified documents is true. CUI, which stands for Controlled Unclassified Information, refers to the handling and dissemination requirements of unclassified information that requires protection. When documents are designated as CUI, they should indeed have the acronym "CUI" or the word "controlled" marked at both the top and bottom on each page to indicate the presence of CUI and to ensure that they are handled appropriately. This measure is part of the effort to keep sensitive information controlled when it does not warrant a classification level of confidential, secret, or top secret, but still needs to be safeguarded from public disclosure.