RES764 – 418 – further noting that, according to Annex 1 to Resolution 27 (Rev.WRC-12), the reference of material which is incorporated by reference on a mandatory basis must be explicit, specifying the specific part of the text, if appropriate, resolves to invite the ITU Radiocommunication Sector 1 to investigate the technical and regulatory impacts on the services referred to in Nos. 5.447F and 5.450A that would result from referencing Recommendation ITU-R M.1638-1 in place of Recommendation ITU-R M.1638-0 in those footnotes, while ensuring that no undue constraints are imposed on the services referenced in these footnotes; 2 to investigate the technical and regulatory impacts on the services referred to in Nos 5.447F and 5.450A that would result from adding a new reference to Recommendation ITU-R M.1849-1 to these footnotes, while ensuring that no undue constraints are imposed on the services referenced in these footnotes, instructs the Director of the Radiocommunication Bureau to include the results of these studies in the Director’s Report to WRC-19 for consideration of any regulatory action in response to resolves to invite the ITU Radiocommunication Sector above.