The entry category does not include special namespaces that are used for various purposes, such as:
the Wikipedia namespace for materials that can be linked to Wikipedia (e.g. Wikipedia: Statistics and its discussion board);
the discussion namespace for discussing the contents of pages (e.g. Talk: Mathematics);
the Advanced namespace, whose pages are created automatically (eg Advanced: Recentchanges);
the editor namespace for Wikipedia authors' pages (e.g. Editor: grin);
several Image namespace pages that contain image description and owner information (e.g. Image: Wikipedia_logo.png)
Special or truncated content
There are many "non-articles" in the article namespace, such as:
the Home page
plenty of explanatory pages that provide a choice between articles with the same name;
plenty of redirect sheets that transfer from one sheet to another;
there are plenty of very short "stub" pages that don't count as a final article yet (these pages often don't even contain links). contains a reference ’.
Quality of articles
The quality of articles varies widely, from high-level featured articles to articles marked for deletion. There are some that are quite long and of good quality in terms of content, on the other hand, there are some that are very short - mostly stumps - and of lower quality.
Protected sheets, Category: Protected sheets
Wikipedia: Structure of articles