This problem applies to ALL "Communities", not just Wiki, but there is no "Category" for Community. You will need to move it to a more appropriate category to get this bug fixed.
In the Add Topic (edit) window, the Category drop-down list has over 300 items, in no particular order, and is thus virtually impossible to use.
This makes it very difficult for users to post to this Community, or inclined to post to the wrong Community.
I had to use the browser Inspect feature to capture the HTML from the drop down list so I could put it into a text editor (after reformatting the HTML) and then use search to find the category I wanted.
At the very least, sort the darn list alphabetically. This would result in only two places to look: items prefixed by "Zoho", and items not prefixed by "Zoho". Better than attempting to slowly scroll the entire 300+ item list in a 4-item-long drop-down window trying to spot the best choice for the topic at hand. (Obviously it would be better to either prefix every item with "Zoho", or no items.)
Also add a Category for this Community forum apparatus, so you can get feedback on this environment.
Graham