I found this topic doing a search and it answered my question exactly. The code
seems to do what I was looking for but there's one strange issue: Some data is
displayed under the wrong subcategory. My table lists events and consists of
four columns that are sorted by 'location'. My subcategories display each
location and then the dates below it. However, I found out that some locations
are not displayed under the correct subcategory although those particular
locations are spelled correctly. Any ideas what I'm doing wrong?