wuu.wikipedia.org/wiki/%E6%A0%87%E5%87%86%E5%90%B4%E8%AF%AD#%E5%8F%83%E8%80%83%E...

The page is about 標準吳語 / 低地吳語, which it itself describes as an internet-created common language / artificial standard for Wu speakers, not the entire Wu language group. But the code shown here, wuu, is officially assigned to Wu Chinese broadly.

Hard evidence:

• The official ISO 639-3 entry for wuu says “Wu Chinese [wuu]” and marks it as an active code for a living individual language.
• Glottolog likewise maps ISO 639-3 wuu to “Wu Chinese” (wuch1236), not to a separate language called “Standard Wu” or “Lowland Wu”.
• A separate language-resource database also lists wuu as Chinese, Wu with tens of millions of speakers, which clearly does not match the article’s own description of this subject as a constructed/common standard with no native-speaker community.

So the problem is not that wuu is invalid; it is that the article assigns a code for Wu Chinese in general to a specific constructed standard proposal. That is factually misleading.