Schema element "`b:UnitID`"

A unique label for a b:unit, within a Namespace.

Definitions

<simpleType name="UnitID">
  <restriction base="NMTOKEN" />
</simpleType>

Description

The UnitID uniquely identifies a b:unit within a b:Namespace. You may best compare this with a filename within a directory.

The UnitID may be derived from the name, with some encoding as defined by the b:rules.

Discussion

Uniqueness of UnitIDs within XML messages

The uniqueness of UnitIDs is preserved within a Collection. However, (XML) messages between clients and servers may contain multiple Units from different Collection which may use relations (b:has) in relative addressing form. Hence, you always MUST be aware of the context in which the UnitID is used to interpret it correctly.

This possible non-uniqueness is incompatible with XMLs concept of IDs.

From Unit name to UnitID

When a Unit is created without explicit (unique) id, then one is derived from its name (which is NFKC normalized). It depends on the active b:rules which characters are removed or get escaped ('%'-encoded). This does not need to protect from constructs which are dangerous in the selected store (like file-system).