Describing the digital object with metadata

A metadata element <md> can either wrap the metadata (mdWrap) or reference it in an external location (mdRef) or both. For example, a MODS record can be encoded in XML and embedded into the metadata section or a MARC record could be included in binary format. Alternately, the metadata section may simply identify the type of metadata it represents (for example MARC, EAD), and point to this metadata in its external location via a URI. This is done by the metadata Wrap <mdWrap> and metadata Reference <mdRef> elements, which are discussed in more detail below.