Does “institution” necessarily refer to the institution or can it be interpreted as“faculty” as well?
(Higher education) institution refers to the legal entity that can be a university orany other type of recognised tertiary education providing institution. A Faculty isonly a part of an institution.

Is (= signing by legal representative) a requirement by the Commission or arecommendation / suggestion?
The signing of the inter-institutional agreements by the legal representative(Rector) or by any other representative duly delegated by the Rector of theinstitution (e.g. the Dean of a Faculty) is a requirement.

Could the “institutional data sheet” substitute part of the inter-institutional agreement?
“Institutional data sheets” differ from institution to institution and contain sometimes even more information than what is asked for in the “inter-institutional” template. All items mentioned in the template should be seen as minimum requirements. It is therefore acceptable to have an inter-institutional agreement with some pages of the template and the institutional data sheets attached providing that they contain the minimum information required.

Can the signature of the Rector be delegated to another representative (e.g. Deans of faculties)?
Yes, on the condition that:
The signature by duly delegated Deans also represents a commitment by other parts of the institution, outside of the Faculty for which they are responsible (e.g., the admissions office, international office, student support functions), where that is necessary for the full implementation and respect of the inter-institutional agreement and the learning agreements.
Mobilities / cooperation with other Faculties in that institution are covered by separate inter-institutional agreements signed by their respective Deans (i.e. one Dean cannot sign for the whole institution).