Good post TKN... Zactly, what I'm talking about. I was a NATA signatory in a Cal and Testing Lab in the 90"s
A bit of steel plate with a pair of bolts may as well be MA15+ rated and only used after 8:30 at night.
Rated equipment has a WWL (or SWL old school) which is then identified on the equipment or is manufactured against a minimum Standard and rated accordingly.
The "Nissan Hook" and the "XYZ plate" are equally unrated IMHO. Sure one "might" be stronger than the other but as too which one and what load you can apply, who the Hell knows... "Rated" Pfffft, yeah, right... until a manufacturer publishes, attaches or stamps a WWL rating on the gear so you can sue his rrrse if it fails, Rated it is not.