I use this database to check on publisher permissions. http://www.sherpa.ac.uk/romeo/search.php http://www.sherpa.ac.uk/romeo/search.php Authors of IEEE artic

I use this database to check on publisher permissions. http://www.sherpa.ac.uk/romeo/search.php http://www.sherpa.ac.uk/romeo/search.php Authors of IEEE articles can archive pre-print and post-print but they cannot archive publisher's version/PDF. And there are lots of conditions.