Apple Final Cut Pro 5 - Manual (Page 1515)

164 Part II Project Interchange
XML, or eXtensible Markup Language, is a markup language. Markup languages clarify
the content in a document by tagging the elements of the document. A well-known
markup language is HTML, the standard language for writing web pages. The benefit of
working with XML is that it is an open standard. The structure and rules for working
with XML documents are well documented by the World Wide Web Consortium
(
http://www.w3c.org ). XML is also quite simple and human-readable: You can view an
XML file in any text editing application and even edit its content. Because XML is an
open standard, anyone with sufficient understanding can process an XML document
into other formats, such as plain text, HTML, or even other XML formats.
Tags and Elements
Tagging content gives the content of a document structure and specific meaning. Each
tag defines an element of the document. For example, compare the following excerpts
from a text file before and after tags have been added:
Original text file
Coffee house wide shot
17
300
Good
Tagged document
<clip>
<name>Coffee house wide shot</name>
<reel>17</reel>
<duration>300</duration>
<good>TRUE</good>
</clip>
In the original text file, you have to make assumptions about the meaning of the
numbers 17 and 300. In the tagged document, the tags clarifies that 17 is actually the
reel name of a clip, and 300 is the clip duration (in frames).
In XML, elements can contain other elements. In the example above, the <clip>
element encompasses all of the other elements.
Most markup languages have a limited set of tags and rules about how the elements
can be ordered hierarchically. For example, an HTML document can have a
<p> element (this is a paragraph element) but if you wanted to add a <sentence>
element, this would not be recognized by HTML-aware applications without altering
the entire HTML standard.