Use radio buttons in product settings

[Diggo11]

I'm trying to write a product with settings, but I cannot seem to get radio buttons to work. From another mod I've seen, they use the following xml:

<setting displayorder="130" varname="ercufo">
    <datatype>number</datatype>
    <optioncode>radio:piped 0|Forum Multiplier overides Usergroup 1|Usergroup Multiplier overides Forum</optioncode>
    <defaultvalue>1</defaultvalue>
</setting>

However I cannot seem to get this type of optioncode to work at all, regardless of what datatype and values I set. Can someone explain how to set this up properly?