The SpaceServer and the underlying SpaceEngine (the data store) use XML as a way of structuring data. While our interfaces have selected several elements to query on, you can specify any of the elements and attributes in the Document Type Definition (DTD) that was used to check data into the SpaceServer.

       In our world of SpaceServers, the best way to understand what kind of query you can make is to look at the two DTD's that define the skulked data available. Currently, our SpaceServer is aware of two kinds of data:

Current DTDs
The EDGAR.Space DTD		SEC EDGAR Documents (doc.edgar)
The RFC.Space DTD		Internet RFCs (doc.rfc)

       A full tutorial on XML is beyond the scope of this section. Excellent information on XML is available from the following sources:

XML Resources
XML.COM		Run by O'Reilly and Associates, XML.COM contains one of the best overviews of the XML world. Particularly recommended is Tim Bray's excellent Annotated XML 1.0.
XML Authority 1.0		For those of you developing XML DTD's (and the best way to learn XML is to develop a DTD), we recommend XML Authority 1.0, made by Extensibility.
Others		The world of authoring tools for XML is far behind the world of standards, but on the low end you might consider Microsoft's XML Notepad (which works well with MSIE 5.0). On the high end (read expensive), the XML world has been abuzz with SoftQuad Software's XMetaL. SoftQuad took the XML world by storm with their recent double-Clark, drafting one James Clark on the Board of Directors and the other James Clark in a development relationship.