This variable defines the character set encoding that will be used by the xml-rpc client and server to decode the received messages, when a specific charset declaration is not found (in the messages sent non-ascii chars are always encoded using character references, so that the produced xml is valid regardless of the charset encoding assumed).

Allowed values: "UTF8", "ISO-8859-1", "ASCII".

Note that the appropriate RFC actually mandates that XML received over HTTP without indication of charset encoding be treated as US-ASCII, but many servers and clients 'in the wild' violate the standard, and assume the default encoding is UTF-8.

$xmlrpc_internalencoding = "ISO-8859-1";This variable defines the character set encoding that the library uses to transparently encode into valid XML the xml-rpc values created by the user and to re-encode the received xml-rpc values when it passes them to the PHP application. It only affects xml-rpc values of string type. It is a separate value from xmlrpc_defencoding, allowing e.g. to send/receive xml messages encoded on-the-wire in US-ASCII and process them as UTF-8. It defaults to the character set used internally by PHP (unless you are running an MBString-enabled installation), so you should change it only in special situations, if e.g. the string values exchanged in the xml-rpc messages are directly inserted into / fetched from a database configured to return UTF8 encoded strings to PHP. Example usage:

<?php

include('xmlrpc.inc');
$xmlrpc_internalencoding = 'UTF-8'; // this has to be set after the inclusion above
$v = new xmlrpcval('κόσμε'); // This xmlrpc value will be correctly serialized as the greek word 'kosme'

$xmlrpcName = "XML-RPC for PHP";The string representation of the name of the XML-RPC for PHP library. It is used by the client for building the User-Agent HTTP header that is sent with every request to the server. You can change its value if you need to customize the User-Agent string.

$xmlrpcVersion = "2.2";The string representation of the version number of the XML-RPC for PHP library in use. It is used by the client for building the User-Agent HTTP header that is sent with every request to the server. You can change its value if you need to customize the User-Agent string.

When set to TRUE, the lib will enable support for the <NIL/> (and <EX:NIL/>) xmlrpc value, as per the extension to the standard proposed here. This means that <NIL/> and <EX:NIL/> tags received will be parsed as valid xmlrpc, and the corresponding xmlrpcvals will return "null" for scalarTyp().

When set to TRUE, php NULL values encoded into xmlrpcval objects get serialized using the <EX:NIL/> tag instead of <NIL/>. Please note that both forms are always accepted as input regardless of the value of this variable.