Understanding Privileges

Hello, all.

I'm  working  on docs for Xaraya and I've some questions about Roles &
Privileges.

1.  Is  there a special syntax for privileges names? Should we use only
English names/characters?

2. What is 'realms' and how we can use it practically?

3.  Are there some rules of privileges & groups priority in privileges
(except levels)? For example - PN.

4. Are access levels has inheritance?

PS
I've read this:
http://www.drewvogel.com/XarDB/ch12s01.html

Thanks in advance,
-- 
Best regards,
 Artem                          mailto:[email protected]