First observed on es.wiktionary during the August release of CatWatch, but I hadn't the time to confirm this properly. We have several categories of the form `Categoría:Wikcionario:xx`, which translates to the canonical names `Category:Project:xx`. It must be noted that the category's title starts from the second member (`Wikcionario:xx`); however, CatWatch would skip the `Category:` part and treat `Project:` (or whatever alias is used) as the new namespace prefix.
This has been reproduced on test.wikipedia:
# Create [[https://test.wikipedia.org/wiki/Category:Project:CatWatchTest|Category:Project:CatWatchTest]]
# Add a link to this category somewhere: [[https://test.wikipedia.org/w/index.php?title=User:Peter_Bowman/misc&diff=251834&oldid=243691|edit]]
# Take a look at the RC:
```
16:46 Wikipedia:CatWatchTest . . (0) . . Peter Bowman (talk | contribs) (User:Peter Bowman/misc added to category) (diff | hist)
```
The `Project:` bit was resolved to `Wikipedia:` and the RC link points now to an incorrect title: `[[Wikipedia:CatWatchTest]]`.