This European Standard specifies the characteristics of electronic representation of Learning Opportunities in order to facilitate their advertising and subsequent discovery by prospective learners. Key users of the standard will be: - those who provide opportunities for learning and wish to advertise them; - those who offer electronic search services that aggregate results from multiple Learning Opportunity providers; - those who wish to compare Learning Opportunities that have been represented electronically. This European Standard specifies an abstract model for representing Learning Opportunities. The model specifies three resources about which metadata can be stored to facilitate advertising of Learning Opportunities: a) the Learning Opportunity Provider; b) the Learning Opportunity Specification; and c) the Learning Opportunity Instance. This European Standard specifies the characteristics of relations between the three resources and recommends a core set of metadata for each.