This fifth report of activities of the Linz Zoocode Committee is devoted to a detailed survey of the problems raised by the current Rules of the Code, published in 2012, regarding the nomenclatural availability of works published online and registered on the database Zoobank. It points to various deficiencies in these Rules and in the conception and functioning of Zoobank, which result in uncertainties regarding the availability of these works and of their various versions. It proposes new wordings for these Rules, as well as for the terminology used regarding electronic publications.