In level 1, support for the XPath syntax is required. Optionally, a repository may support the SQL syntax (see 8.5 Searching Repository Content with SQL). Implementations may also support additional languages.
XPath is a search language originally designed for selecting elements from an XML document. Since a workspace, like an XML document, can be viewed as a tree structure, XPath provides a convenient syntax for searching workspace content. The main prerequisite for providing XPath querying is to establish an XML mapping of the workspace tree. Having already established two such mappings (system and document view) for purposes of serialization and deserialization, we simply re-use one of them, the document view, as the basis against which an XPath query is run (see 6.4.2 Document View XML Mapping).