Returns the value of LongName attribute. This attribute represents long name for a zone, used for informal purposes. It should be used, if available, in conjunction with the inherited Name attribute.

Returns the value of LongName attribute.

• NOTE: In many scenarios the Name attribute refers to the short name or number of a zone, and the LongName refers to the full name.
• IFC4 CHANGE: The attribute has been added at the end of the entity definition.