Understanding EAD and XML

This isn’t a full overview of EAD or XML, but rather some basics that you should find helpful when learning EAD and using this site.

What is XML?

XML is eXtensible Markup Language. It is a language used to encode data. It’s like HTML, but incredibly flexible. You can call a tag (also called an “element,” which I will use interchangeably on this site) whatever you want. If you want, you can write your own DTD (Document Type Declaration) or Schema which codifies a set of XML tags and describes how they interact with each other.

The only real rules of XML are that you nest your tags within each other and that you follow any rules of a schema/DTD you’re using. This site will each you how the EAD Schema works.

Nesting is pretty straightforward. It means that:

<tag1>
	<tag2>
	</tag1>
</tag2>

is NOT ok. Instead, it should look like:

<tag1>
	<tag2>
	</tag2>
</tag1>

Another way to look at that would be: <strong>The entire city was <em>in flames</strong></em> is WRONG because the <em> should be closed before the <strong> and <strong>The entire city was <em>in flames</em></strong> is correct.

You’ll occasionally see things called “wrapper” elements. These elements don’t contain any text, only other EAD elements. They’re designed for grouping elements which are related, rather than for specifically encoding text. Other elements can handle both plain text and subelements.

The Mozilla Developer Network has a good introduction to XML and links to other places where you can learn more about it.

What is EAD?

EAD stands for Encoded Archival Description. It is a non-proprietary XML Schema (and a slightly-older DTD…for most people, the difference between the two won’t be especially important) created by and for archivists to be used in the creation of XML-based finding aids. These finding aids can be read by browsers, search tools, etc. Various programs can convert them into PDFs or save them in databases where they can be edited and re-exported.

EAD finding aids can be created manually in text or XML editors, through specially-designed Access (and other) database exports, and through special EAD-creating software such as Archivists’ Toolkit and Archon. ArchivesSpace is a next-generation descriptive information management system which is still under construction.

This site will assist you in learning the elements specific to EAD and how they should be used to describe a collection for a finding aid/index/guide/inventory. It includes links to many other sites which can help you learn even more.