Adding a new category through the Site Settings section of your account allows you to include a category description and select the option to nest a new category below a Top level Category.
Selecting a parent category will insert the new category under the Top level category.
All posts must be assigned a category. By default, the category is Uncategorized. You can change the default category through Manage →Settings → Writing → Categories.
Changing the default Category.
While it is not possible to delete the “Uncategorized” Category, you can rename it to whatever you want.
Categories can only be added to Posts, but not Pages. If you want to nest pages under other pages, use Page Attributes → Parent Page in Documents Settings for that page. We have more details on Page Attributes here.
Go to My Sites → Site → Posts
Click on the post you want to assign to a category.
Under Document Settings on the right, expand the Category option.
Click the checkbox next to the category you want the post to be assigned to and publish your changes
You can select multiple categories for a single post to show in. You should not add more than five to 15 categories and tags to a post.
You can remove a post from a category by unchecking the box next to the category name.
New Category from Within A Post
It is possible to quickly add a new category through the post’s Document Settings by clicking on Add New Category.
You will be able to give the category a name, and select a parent category.
If you have added a Category Page to your site’s menu but do not see any posts on the Category Page, or a message that says the content can’t be found, this means no posts have been assigned to that category. Once you add posts to the category they will automatically show on the Category Page.
Your posts will appear in the topics listings of any tags or categories you use. Therefore, assigning tags and categories to your post increases the chance that other WordPress.com users will see your content.
However, you don’t want irrelevant content showing up on the topics listings or search, and neither do we. That’s why we limit the number of tags and categories that can be used on a public topic listing. Five to 15 tags (or categories, or a combination of the two) is a good number to add to each of your posts. The more categories you use, the less likely it is that your post will be selected for inclusion in the topics listings. Learn more about Topics here.
You can use the WP Admin dashboard to edit your categories in bulk. You can get to this dashboard by adding /wp-admin to the end of your site’s url (e.g.: example.wordpress.com/wp-admin)
On the left menu, you can add new categories and manage existing ones from Posts → Categories in your dashboard.
To bulk delete any categories, check all categories you want deleted, and in the “Bulk Actions” dropdown above the list, select “Delete”, then click the “Apply” button.
If you have added a Category Page to your Menu, and you see a not found, or nothing found, page when you view it, this means there are no posts assigned to that category.
Once you add a post to that category it will automatically show on your Category Page.
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