Joined Cases C-90/11 and C-91/11: Judgment of the Court (Third Chamber) of 15 March 2012 (references for a preliminary ruling from the Bundespatentgericht — Germany) — Alfred Strigl v Deutsches Patent- und Markenamt (Case C-90/11), Securvita Gesellschaft zur Entwicklung alternativer Versicherungskonzepte mbH v Öko-Invest Verlagsgesellschaft mbH (C-91/11) (Trade marks — Directive 2008/95/EC — Grounds for refusal or invalidity — Verbal expressions which consist of a word combination and a sequence of letters identical to the initial letters of those words — Distinctive character — Descriptive character — Assessment criteria)