The types of Cultural Heritage, predominantly in the form of physical or tangible heritage, that are most frequently represented in the collections of institutions, carry the imprimatur of public and official bodies, enjoy some degree of public approbation or otherwise are most commonly  accepted and widely recognised  as heritage. The term ‘authorised Cultural Heritage’ is also sometimes used in this context, although no formal process of certification or listing is involved. By definition, therefore, all other forms of Cultural Heritage – intangible, popular, and everyday – may be considered to lie outside of the ‘mainstream’.