"The Regulation governing the capital adequacy of institutions, groups of institutions and financial holding groups (Solvency Regulation) of 14 December 2006 was published in the Federal Law Gazette (Bundesgesetzblatt) 2006, part I, No 61, p 2926 ff on 20 December 2006 and came into force on 1 January 2007."
http://www.bundesbank.de/bankenaufsicht/banke...

"The Solvency Ordinance (Solvabilitätsverordnung – SolvV), which came into force on 1 January 2007, has replaced the earlier Principle I concerning the Capital of Institutions."
http://www.bafin.de/nn_1946138/EN/Companies/B...

Solvabilität is solvency; "solvability" is a rare and somewhat awkward word for whether or not a problem can be solved.
That aside, I'm not crazy about rendering Verordnung as "ordinance" (which at least in the US generally refers to something enacted by a local government), but it may be too well entrenched to do anything about at this point.