gml:catalogSymbol 

The catalogSymbol is the preferred lexical symbol used for this unit of measure.
The codeSpace attribute in gml:CodeType identifies a namespace for the catalog symbol value, and might reference the external catalog. The string value in gml:CodeType contains the value of a symbol that should be unique within this catalog namespace. This symbol often appears explicitly in the catalog, but it could be a combination of symbols using a specified algebra of units.

Element Information

Model

Attributes

QName Type Fixed Default Use Inheritable Annotation
codeSpace anyURI optional

Used By

Complex Types gml:BaseUnitType, gml:ConventionalUnitType, gml:DerivedUnitType, gml:UnitDefinitionType

Source 

<element name="catalogSymbol" type="gml:CodeType">
  <annotation>
    <documentation>The catalogSymbol is the preferred lexical symbol used for this unit of measure. The codeSpace attribute in gml:CodeType identifies a namespace for the catalog symbol value, and might reference the external catalog. The string value in gml:CodeType contains the value of a symbol that should be unique within this catalog namespace. This symbol often appears explicitly in the catalog, but it could be a combination of symbols using a specified algebra of units.</documentation>
  </annotation>
</element>

Sample