The page is displaying in a generic style that has nothing to do with my layout (or any layout that I know of), but it is displaying a list of entries with that tag. I am using S1. (Of course, S1 has to have the ability to sort by tag in order for there to be any point in displaying S1 users' tags on S2 users' Friends pages.)
The Tags FAQs state that tags can not be used to sort entries in S1. While the tag links will not display on an S1 layout, they do display on the comment pages and can be used to sort my entries while I am using S1.
227: "If you are using the S1 style system, you can define tags for your entries, but you will not be able to see them or sort your journal using them."
To be correct, this should read "If you are using the S1 style system, you can define tags for your entries. You will not be able to see them on your journal, but they will display on the post/read comments pages for individual entries." (or whatever those pages are officially called)
226: "Then, if your journal is using the S2 style system, you can display only the entries with that particular tag.
...If you are using the S2 style system, the tags will then appear when you view your journal. In S1, the tags will display only on comments pages. Each entry's tags will be links. The link for each tag leads to:
http://www.livejournal.com/users/exampleusername/tag/tagname
Replace exampleusername with your username, and tagname with the name of the tag you wish to view. You will be able to see the last 100 entries from your journal with that tag. This will not work if your journal is using the S1 style system."
This will be correct if the italicized portions are removed and the bold portion added.