Thanks a lot for answering Scott ,
I used to on my one site than I relaised that q2a is not seo friendly.
When for Tags , Categories and Urls it is not suitable.
In my language there are accents like û , ê , î but when you write as a tag it happens something different.That is not good for seo
Here example but no answer
Also today I found another problem for username.When you want to take a name with space
for example "Im Scott" in url /Im+Scott if you want to take this name "ImScott" Than you can take too.So why developers dont make this normal like "Im Scott" will be "im-scott" that is has to be simple doing this .
Thanks a lot again.
Edited: I found solution for category and post url. But still have tags and username issue.