What Is XML?

XML stands for eXtensible Markup Language.

Like many technologies Adobe supports in its software, XML is an industry standard. The implementation of open standards in Adobe software means that Adobe's tools are designed to work in the context of larger workflows, rather than limit users to a proprietary, Adobe-only world.

But what do XML and open standards have to do with print workflows or InCopy? We are all familiar with formatting a document for visual presentation in a magazine, newspaper, or Web site. Defining the logical structure of a story with XML is a profoundly different approach to a document. XML is a powerful way to mark up the information in your InCopy file to describe its contents, as opposed to its design. InCopy and InDesign use the word tag to describe the process of marking up a document, so we use that word in this chapter. (Tag and other terms are explained in the next section.) When you assign paragraph styles, character styles, or color swatches to text in your document, you're formatting the document for visual presentation. Using XML enables you to divorce form from content, which is very useful for repurposing content. For instance, the same story you write for the front page of the newspaper might also be used on the paper's Web site. It will look very different in each place, but the content is still the same. The structure of your document might by broken down into a headline, byline, body, and caption. It is only in terms of the form of your story that it likely looks very different in print and on the Web. That's what we mean when we say XML describes the contents of a document (headline, sub-head, byline, and body) but not the form (font, size, alignment, and color).

XML Terminology

None of the following terms is unique to InCopy's use of XML, but you'll need to be familiar with them in order to use InCopy's XML features.

• Tag (noun) is XML markup describing an element's content. In InCopy, each tag has a unique name and identifying color. Some common tags used in a publishing workflow include headline, byline, body, and caption. XML must be well-formed, meaning that an opening tag, such as <headline> must have a matching closing tag </headline>. The content in between the two tags is referred to as tagged content.

• Tag (verb) is to assign an XML element to the content, in other words, to "mark up."

• Element is any item defined by opening and closing tags in an XML file. InCopy automatically creates well-formed XML, so when you tag content, all necessary opening and closing tags are written for you.

• Attribute is a single property of an element. In XML an attribute is required to have a value. For example, to state the location of a particular author, one might use an element called <author> with an attribute of "location" set to a value of "New York": <author location="New York"> </author>.

• Structure is the way the elements fit together in a logical outline of the content.

• DTD [Document Type Definition] is the set of rules for the structure of a particular file: what elements and attributes are permitted in a file and the order in which they must appear and/or are assigned. A similar method of setting up rules that govern the structure of a document is to use a set of XML-based statements called a schema, but at this time InCopy supports DTDs only.

• Validate is to confirm that the XML in your document conforms to the DTD you've associated with it.

Tags as Building Blocks of XML

Tags are the glue connecting an element in the structure with its page object. Without tags, you cannot have XML. Although you can change the name of a tag after its creation, it is helpful to decide in advance on the tags you will need to use for your document. If the parts of the structure of your file boil down to headline, byline, body, and caption, those would be great tags to create. Often, text styles in your InCopy story provide the basis for deciding on a set of tag names. In some cases, InCopy users will create tags from scratch; in others, InCopy users will load tags from other sources into their current InCopy stories. Either way, you manage tags in the Tags palette.