QUO is not a reserved word. It should not effect the results of this function call. Can you post the exact syntax that you used?
Here are the steps I used to get the value list name:
Set Variable [ $activefieldname ; Value:Get(ActiveFieldTableName) & "::" & Get(ActiveFieldName) ]
Set Variable [ $valuelistname ; Value:Right(FieldStyle ( Get(FileName) ; Get(LayoutName) ; $activefieldname );Length(FieldStyle ( Get(FileName) ; Get(LayoutName) ; $activefieldname )) -10) ]
When I used this on a layout named "INVC" it worked. When I used this on a layout named "QUO" it did not work, and $valuelistname did not resolve to anything.
I changed the layout name to "QUOT" and it worked!
I don't understand it. I spent hours on this one...
The problem would appear to be the number of characters in your layout name. Note that INVC and QUOT are both 4 letters long where QUO is only 3. The right function is extracting text based on arbitrary numbers of characters so this difference in the number of letters in the name is probably the reason.
Try using the RightWordsand wordcount functions.
RIghtWords ( FIeldStyle ( ) ; Wordcount ( FieldStyle ( ) ) - 1 )