Notice concerning procedures for communications to the Commission pursuant to Articles 4 and 5 of Commission Regulation (EEC) No 2671/88 of 26 July 1988 on the application of Article 85 (3) of the Treaty to certain categories of agreements between undertakings, decisions of associations of undertakings and concerted practices concerning joint planning and coordination of capacity, sharing of revenue and consultations on tariffs on scheduled air services and slot allocation at airports