Case C-142/18: Judgment of the Court (Fourth Chamber) of 5 June 2019 (request for a preliminary ruling from the cour d’appel de Bruxelles — Belgium) — Skype Communications Sàrl v Institut belge des services postaux et des télécommunications (IBPT) (Reference for a preliminary ruling — Electronic communications networks and services — Directive 2002/21/EC — Article 2(c) — Notion of ‘electronic communications service’ — Transmission of signals — Voice over Internet Protocol (VoIP) service to fixed or mobile telephone numbers — SkypeOut service)