In a statement to BuzzFeed, an LSU spokesman said the sign was not sanctioned by the university, which appears to be the victim of an age-old joke:
The document in question is in no way an official communication created by LSU Residential Life staff or any other official LSU entity. The university believes this document was either produced by an individual who obtained the official university logo and used it without official consent, and/or is part of an on-going Internet prank. LSU Residential Life will investigate the whereabouts of this document and if found, will remove it and any or all facsimiles immediately.