Learning XML

2.1. The Anatomy of a Document

Example 2.1 shows a bite-sized XML example. Let's take a look.

Example 2.1. A Small XML Document

<?xml version="1.0"?> <time-o-gram pri="important"> <to>Sarah</to> <subject>Reminder</subject> <message>Don't forget to recharge K-9 <emphasis>twice a day</emphasis>. Also, I think we should have his bearings checked out. See you soon (or late). I have a date with some <villain>Daleks</villain>... </message> <from>The Doctor</from> </time-o-gram>

It's a goofy example, but perfectly acceptable XML. XML lets you name the parts anything you want, unlike HTML, which limits you to predefined tag names. XML doesn't care how you're going to use the document, how it will appear when formatted, or even what the names of the elements mean. All that matters is that you follow the basic rules for markup described in this chapter. This is not to say that matters of organization aren't important, however. You should choose element names that make sense in the context of the document, instead of random things like signs of the zodiac. This is more for your benefit and the benefit of the people using your XML application than anything else.

This example, like all XML, consists of content interspersed with markup symbols. The angle brackets (<>) and the names they enclose are called tags. Tags demarcate and label the parts of the document, and add other information that helps define the structure. The text between the tags is the content of the document, raw information ...