Arxiving accepted manuscript after publication in Elsevier/IEEE/etc The Elsevier policies state:


  Authors can share their accepted manuscript: by updating a preprint in arXiv or RePEc with the accepted manuscript


I haven’t arxived a preprint; the paper is published already; yet I’d still like to arxive the accepted version – does above sentence imply that I’m only allowed to update an existing Arxiv entry but not create a new one now?



IEEE policies have a similar phrasing:


  
  Electronic Preprints. Before submitting an article to an IEEE publication, authors frequently post their manuscripts to their own
  web site, their employers site, or to another server that invites
  constructive comment from colleagues.Upon submission of an article to
  IEEE, an author is required to transfer copyright in the article to
  IEEE, and the author must update any previously posted version of the
  article with a prominently displayed IEEE copyright notice. Upon
  publication of an article by the IEEE, the author must replace any
  previously posted electronic versions of the article with either (1)
  the full citation to the IEEE work with a Digital Object Identifier
  (DOI) or link to the article abstract in IEEE Xplore, or (2) the
  accepted version only (not the IEEE-published version), including the
  IEEE copyright notice and full citation, with a link to the final,
  published article in IEEE Xplore.
I do not have a definitive answer, but I have considered the matter and came to the conclusion that you can only update an already arXived preprint, not arXive it fresh after publication. Note that as far as Elsevier is concerned, this is a recent change, which happened when they revised their whole copyright agreement. Thus decade long habits may not apply anymore. Or maybe they do, because if there is one clear thing, it is that Elsevier's policy has been significantly obfuscated.

However, there are some countries (France shall join them soon) where by law, one can post their postprints on a repository after an embargo whatever the copyright agreement says. Many publishers also allow this (but embargoes are several years long for some Elsevier journals, if I remember well).