It's best for SEO purposes that we use the main page keywords in our urls For example stackoverflow uses this technique too.
http://stackoverflow.com/questions/show-utf8-characters-in-console
I wonder if it's okay to use something like:
http://www.mobadele.com/categories/طلا-نفره
No, it is not. Officially you have to URL-encode them.
http://en.wikipedia.org/wiki/Percent-encoding
I am not sure how far the implementation of IRI http://en.wikipedia.org/wiki/Internationalized_Resource_Identifier is, It may work in reality, but I have ran into all kind of trouble with Russian characters in URL's and query strings so I got rid of them.
this question is answered here https://stackoverflow.com/questions/3865020/is-it-good-idea-to-use-url-names-with-special-characters/3967220#3967220
Short answer: not if you want to follow the rules.
RFC 1738 describes the required encoding and the rationale in section 2.2:
Thus, only alphanumerics, the special characters "$-_.+!*'(),", and reserved characters used for their reserved purposes may be used unencoded within a URL.
