TheBeanTeam:OK this is complicated but if you are in the post a waymark page and you begin to select subcategories I found at least one issue.
If you drill down starting with Buildings the next list gives you an option for converted train stations.
Then you can select the category. To my knowlede there is no category for "converted train stations".
I even when searching for one thinking maybe there was one I didn't know about but I couldn't find it.
Is this an error? Wonder if there are others.
Edit to add that the subcategory Yard Art Silhouettes subcategory in the Art/Music section is another that doesn't appear to exist.
Interesting. We'll investigate, thanks!