Special characters in handles
Since handles are used for your storefront navigation for products, collections, blogs and pages, they must use alpha-numeric characters (a-z, 0 to 9) without accents (such as umlauts, and other diacriticals), nor characters such as @ or # etc., and no spaces.
Spaces will be converted to hyphens, other characters may be stripped entirely or converted to an equivalent standard ASCII character.
Example of characters that aren't allowed:
After trying to save a handle like this you will end up with a handle looking like: