Processing Instructions are information for the application. PI's allow documents to contain instructions for applications. They are not really of interest to the XML parser. Instead, the instructions are passed to the application using the parser, because the purpose of processing instructions is to represent special instructions for the application.Like comments, they are not textually part of the XML document. All processing instructions, including the XML declaration, begin with <? and end with ?>. Following the initial <?, you will find the name of the processing instruction. The PI begins with the PITarget used to identify the application to which the instruction is directed. <?name pidata?>
<?xml version="1.0"? encoding="UTF-8" standalone="yes"?> | Version Declaration is a form of PI. A particular document may have processing instructions for several different applications, so the processing instruction target (PITarget), right after the opening <?, identifies the target application for this processing instruction. |
