++++ 1.Community law - Principles - Equal treatment - Discrimination by reason of nationality - Prohibition - Covert discrimination - Included ( EEC Treaty, Arts 52 and 59 ) 2.Freedom of movement - Freedom of establishment - Freedom to provide services - Derogations - Activities connected with the exercise of official authority - Technical activities in the field of data processing carried out for the public authorities - Excluded ( EEC Treaty, Arts 52, 55, 1st paragraph, 59 and 66 ) 3.Freedom of movement - Freedom of establishment - Freedom to provide services - Procedures for the award of public supply contracts - National legislation giving companies controlled by the national public sector exclusive rights to supply goods in the field of data processing - Not permissible ( EEC Treaty, Arts 52 and 59; Council Directive 77/62 )