I don't think there is a rule that your own work must be tagged with Show HN. You can opt-in to Show HN if

> you've made something that other people can play with. HN users can try it out, give you feedback, and ask questions in the thread. [1]

but afaik nothing in the guidelines [2] requires it.

1: https://news.ycombinator.com/showhn.html

2: https://news.ycombinator.com/newsguidelines.html

Correct. And thanks for the remark.