MySQL create an Anonymous or limited access only account

Sometime it is necessary to create an anonymous or limited access only account. This allows anonymous user to use MySQL server. I received following criteria

[*] Create a user called anonymous

[*] Set up read and write permission to account

[*] anonymous cannot set or update password (remember if one user changes the password, no other anonymous login can be accepted again).

[*] Grant anonymous access to table called xyz

Please note that this anonymous user is for internal WAN/Lan user and not for Internet users.

However, I have noticed default anonymous mysql account.
$ mysql -u anonymous

MySQL allows to login in anonymous user (or any user) from localhost. However this user is not allowed to use any / critical database such as mysql or set password:
$ mysql -u anonymous
Output:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2630835 to server version: 4.1.20
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

Try to use mysql database:
mysql> use mysql;
Output:

ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'mysql'

Try to setup password:
mysql> SET PASSWORD FOR anonymous@localhost=PASSWORD('secrete');
Output:

ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'mysql'

So all I have to do is set permission to table called xyz with GRANT SQL command.
$ mysql -u root -p
Now grant permission to xyz table:
mysql> use dbnane; mysql> GRANT SELECT ON xyz TO ''@localhost

Now any anonymous user can connect to mysql database server and query xyz table from localhost.