Solaris 10: extended attributes, how to create it?

Some Solaris 10 commands (ls, find..) support extended attributes. With runat is possible to copy and list extended attributes. But how to create/insert an extended attribute in a file? On Linux we have chattr (chattr +i...chattr +m¹). On Solaris 10? Thanks 1 DON'T TEST IF YOU DON'T KNOW WHAT THEY DID!