I wanted to create a new category, "Newsletter," that I can use to tag which posts appear in my weekly newsletter. But I don't want that "Newsletter" category to appear on the blog itself.

The solution seems relatively simple. I created the "Newsletter" category, added some posts, and then configured my newsletter in Micro.blog to only send posts using the "Newsletter” category.

I then went to my Design > CSS and added the following snippet. This will work in the Cards Theme. You will need to adjust the CSS to work with whatever theme you're using. It will look for the category containing the URL "newsletter" and hide the parent element.

.archive_categories p:has(a[href*="newsletter”]){
  display: none;
}

Now, I can create a "hidden" category in Micro.blog for specific purposes, like filtering my newsletter.