The identifier of the current element is printed by:

id

If an element has an identifying property, the string representation of that property forms its identifier. If an element has no identifying property, e.g. if it has no properties, the name of its type forms its identifier. If an element has an identifier generator, the output of that generator forms the identifier.

The command can also be used to access elements in containing loops by following the command with a semicolon and level number: see “Level number” in Section 6.1.9.