Installing phpMyAdmin - Mastering phpMyAdmin 2.8 for Effective MySQL Management - page 23

Servers Defined in the Configuration File
In the server-specific sections of the config.inc.php file, we see lines referring to
$cfg['Servers'][$i] for each server. Here, the variable $i is used so that one
can easily cut and paste whole sections of the configuration file to configure more
servers. While copying such sections, we should take care that the $i++; instruction
that precedes each section and is crucial to delimit the server sections is also copied.
Then, at the end of the sections, the following line controls what happens at startup:
$cfg['ServerDefault'] = 1;
The default value, 1 , means that phpMyAdmin will connect by itself to the first
server defined or present this server choice by default when using advanced
authentication - more on this later in this chapter. We can specify any number, for
the corresponding server-specific section. We can also enter the value 0 , signifying
no default server, in which case phpMyAdmin will present a server choice:
Arbitrary Server
Another mechanism can be used if we want to be able to connect to an undefined
MySQL server. First, we have to set the following parameter:
$cfg['AllowArbitraryServer'] = TRUE;
Then, we need to use the cookie authentication type, explained in the next section.
We will be able to choose the server and enter a username and a password.
This mechanism should probably be used in conjunction
with a reinforced security mechanism (see the Security
section), because any MySQL server accessible from our
web server could be connected to.