The identity of a built-in style is its builtinId, not the name string
(which a file saves in the authoring language). Importers should resolve the
id back to the canonical name so a name="Standard" builtinId="0" foreign
file maps to BuiltInName.Normal.
Canonical built-in style name for an ECMA-376
builtinId(its ordinal), orundefinedfor an unknown id.