I've no idea why i can't add a Page with Name
2011. Wordpress changes the URL Slug to 2011-01.
There is no Post with this Name in my Database. I tried zu flush my rewrite rules but nothing seems to be work.
If i add a Page 2013 it works fine. But only once... If i delete this Page (from Trash) i can't add it again. Wordpress changes the slug to 2013-01. If i change the Post name directly in the database. Nothing happens...
I really wonder why because there is no Post with this Name.