A single metadata (“metadatum”) is represented by a triple: a symbol representing the type, a symbol representing the key, and either a string or a list that represent the value.

The symbol depends on the [metadata key type](00001006030000).
The value also depends somehow on the key type: a set of values is represented as a list, all other values are represented by a string, even if it is a number.

The following table maps key types to symbols and to the type of the value representation.





Examples:

* The title of this zettel is represented as: `(EMPTY-STRING title "Encoding of Sz Metadata")`
* The tags of this zettel are represented as: `(TAG-SET tags ("#api" "#manual" "#reference" "#zettelstore"))`