DEFINITION: Legal Interoperability Requirement ABB is a Requirement that must be met to help achieve legal interoperability. Source: Joinup (https://joinup.ec.europa.eu/sites/default/files/document/2019-06/High-level%20Interoperability%20Requirements%20Solution%20Architecture%20Template%20%28HL%20SAT%29%20Design%20Guidelines_0.pdf) EXAMPLES: The following implementation is an example on how this specific Architecture Building Block (ABB) can be instantiated as a Solution Building Block (SBB): European portals should be compliant with legal and legislative acts such as the General Data Protection Regulation Source: (https://ec.europa.eu/eusurvey/runner/SIQAT_v200?startQuiz=true&surveylanguage=EN)