Descriptive metadata: Embedding binary MARC records
While it is normally preferable to include MARC metadata as MARCXML, or potentially to link to a record in an external system, it is also possible, when needed, to directly include binary data in a METS XML document.
<md ID="dmd003" USE="DESCRIPTIVE">
<mdWrap MIMETYPE="application/marc" MDTYPE="MARC" LABEL="OPAC Record">
<binData>MDI0ODdjam0gIDIyMDA1ODkgYSA0NU0wMDAxMDA...
[Base64-encoded data goes here]
</binData>
</mdWrap>
</md>
See also: Embedding binary data in METS