14 Regulations.36 However, it should be noted that these Staff Regulations are binding on the staff only and not on lobbyists. Furthermore, registration requirements and standards of conduct could be incorporated into or annexed to the Rules of Procedure of the relevant organs.37 They could regulate such elements as meetings with EU officials (MEPs, Commission staff, etc.), access to EU facilities (buildings, official meetings, workshops and other events), membership in expert working groups, speaking in front of EU institutions or at meetings organized by them. Requirements that only registered organisations can receive EU subsidies or contracts with a link with EU policies and lobbying could be included in the EU budget or the Commission and European Parliament guidelines for grants and contracts. As such rules would only regulate the internal organization and decision-making process, they would only be formally binding on the institutions. Hence, Rules of Procedure can only include requirements for lobbyists when they interact with the institutions. The factual impact of such rules depends on their contents and the strictness of their implementation. Generally, such rules can be considered as de facto binding on lobbyists if the latter have to comply with them if they want to interact with the respective institutions. Since this is the primary goal of most lobbyists, such rules would target a significant portion of lobbying activities. However, if lobbyists chose not to have direct contact with the institutions, Rules of Procedure cannot compel them to register. In addition, rules of Procedure could not impose any penal sanctions for non-compliance. Non-compliance with the requirements of the register could only lead to exclusion from the register and refusal of further interactions. The interinstitutional agreement upon which the current system is based is a sui generis instrument, but it also addresses the behavior of those lobbyists which are in contact with the Commission and Parliament. Interinstitutional agreements have therefore similar legal consequences as the Rules of Procedure. They are binding on the institutions and can therefore have similar factual binding effects on lobbyists if they interact with the respective EU organs. However, as pointed out at the outset, the current system is only voluntary. Yet, the EU institutions could strengthen the agreement by including rules which are binding on themselves. 36 See also Dirk Hasler, Die Europäische Transparenzinitiative und “Legislatives Lobbying”, Zeitschrift für europarechtliche Studien 2007, 503 (516 et seq). 37 The legal bases for the Rules of Procedure are Art. 232 (1) TFEU (Parliament) and Art. 249 (1) TFEU (Commission),