In order to settle a bet with one of my colleagues, I would like to find out if VB6 natively supports any unsigned data types.
I believe the answer to be "no", but I can't seem to find any official documentation confirming that. A simple link to a Microsoft document would be an acceptable answer; an historical justification as to why such types are not supported would be an added bonus.
As Kris said, they're not supported, except for the Byte datatype, which is only available as unsigned, as can be seen in this list of datatypes: Data Type Summary
The page mentions VBA, but it also mentions Visual Studio 6.0, and the supported data types were the same.
I don't think you'll find official documentation saying why they didn't add unsigned data types since that's usually the wrong way around in that it probably wasn't a case of "why shouldn't we support this" as much as "would it be worth the extra effort to add this".
Edited to mention the exception of the Byte datatype as pointed out by MarkJ.