Example from the Recommendations 2013. Left: Alleged disilazane ; Right: My version
Clearer example without obvious flaws in alternative structure. Left: Alleged disilazane ; Right: My version
I am confused with the contemporary IUPAC nomenclature of organic compounds. According to Recommendations 93 (available at acdlabs.com), silazanes are heterogeneous hydrides where both terminal atoms are silicon atoms (R-184.108.40.206). The same can be concluded from the general rule on heterogeneous hydrides (R-220.127.116.11). However, in the introductory chapter of Recommendations 2013 (which is freely available at RSC Publishing site) on page 82 the compound given in the image is given two names, with the least priority (non-PIN) variant being 1,1′-(2-ethenyl-1,2,3-trimethyldisilazane-1,3-diyl)bis(ethan-1-one). I am confused by this name, as, by rule R-18.104.22.168, terminal atoms should be lowest in the Hantzsch–Widman order, which preserves unambiguity of the structure. From this rule, I expect disilazane to be something like the structure on the second image (although I acknowledge that the tetravalent nitrogen must be positively charged, which changes the name automatically).
TL;DR So the question is:
Do Recommendations 2013 change something about naming heterogeneous hydrides? And if so, what is now called silazanes?