>>>I am not using TAG() to get index expression. I was using it to get a tag name. And then using TYPE() to see the type of field in the index key. It was working until I got into an issue with the index key UPPER(SUBSTR(...). I don't see how EVALUATE() will help but I will think about it.
>>>
>>>Thank you.
>>
>>I think it should be vartype(evaluate(key())). TYPE(TAG()) is a bit strange anyway.
>
>Vartype(evaluate(key())) works. Thank you very much!

That's what I meant in my original message.