This standard defines the 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. The standard presents an abstract model for representing Learning Opportunities. The model specifies three resources about which metadata can be stored to facilitate advertising of Learning Opportunities: 1. Learning Opportunity Provider; 2. Learning Opportunity Specification; and 3. Learning Opportunity Instance. The standard specifies relations between the three resources and recommends a core set of metadata for each. The model proposed within the standard is not intended to define the electronic representation of Learning Objects in general - the scope of the standard is restricted to definine the electronic representions of Learning Opportunities to facilitate their advertising and subsequent discovery by learners. Metadata collected and presented for the purpose of advertising Learning Opportunities may, of course, be used for other purposes - for instance, providing detailed description of a formal learning opportunity to enrich a transcript that showed a learner's educational history. However, guidance on the specification and organisation of metadata for purposes other than advertising Learning Opportunities is outside the scope of this standard.