Case C-349/11: Order of the Court (Sixth Chamber) of 9 December 2011 (reference for a preliminary ruling from the Tribunal de première instance de Liège — Belgium) — Auditeur du travail v Yangwei SPRL (First subparagraph of Article 104(3) of the Rules of Procedure — Directive 97/81/EC — Administrative obstacles liable to limit the opportunities for part-time work — Obligation to publicise and keep employment contracts and work schedules)