Manuscript Preparation, Copyediting, and Proofreading
Q. I’m editing a series of reports that use abbreviated forms of the sometimes lengthy titles in the footer. Are there any recommended guidelines for abbreviating titles for this purpose (e.g., use of acronyms, elimination of less important prepositional phrases), or is this at the discretion of the author or editor?
A. CMOS doesn’t offer advice on this subject, so I would advise you to keep the reader in mind and phrase running feet or heads in a way that will be most helpful. Acronyms are fine, as is the elimination of less important words. And the editor should specify rather than leave the chopping to the typesetter.