I have the following type:

<type name="PartyIDSource" description="PartyIDSource" presence="constant" length="1" primitiveType="char" semanticType="char">C</type>

And the following field using the type:

<field name="PartyIDSource" id="447" type="PartyIDSource" semanticType="char"/>

This creates the following code in java:

    public byte partyIDSource()
    {
        return (byte)C;
    }

because there's no single quotes around the C, this causes compilation failures , removing the length="1" part does fix it to be "return (byte)57;"