XML glossary

XML glossary

This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.

DTD (Document Type Definition)

The early form of a schema definition file that specifies rules for XML document elements, attributes, and containment relationships.


Inheritance relationships established in an XML for Visio file by means of attributes. The XML for Visio schema includes attributes that establish inheritance between shapes, masters, and styles.

Instance shape

A shape that is based on a master. Instances inherit many of their characteristics from the master. In the Visio user interface, an instance shape is created by dropping a master from a stencil onto the drawing page.


A master appears as a shape in a stencil that you use to create instances, or shapes, based on the master. A master can be made of a single shape, multiple shapes, or a group. Instances inherit many of their characteristics from the master.


Microsoft XML/XSL Parser that implements XSLT 1.0, XPath 1.0, XDR, and SAX2.


A naming convention to use in order to avoid name collisions. In Visio XML documents, xmlns statements specify a schema. For example,


Non-instance shape

A shape that is not an instance of a Master; for example, a shape that is created using the line tool in the user interface, or an Automation method such as DrawRectangle.

Non-void cell

Cells that have known and dedicated result types, such as boolean, color, distance, angle, and so on.


The process of reordering existing elements, adding missing elements, and removing unused elements when Visio loads text data from an XML file that is created or edited outside of Visio (an untrusted file).


Opening a Visio document (or an XML file created outside of Visio), saving it as an XML for Visio document, and then reopening the XML for Visio document with no loss of information between the binary version and the XML for Visio version of the Visio document.


Another term that describes the contents of a sheet. This term is commonly found in the user interface, and the window in which you can view its contents in the user interface is called the ShapeSheet window.


An internal spreadsheet that contains the cells, rows, and sections that define a document, page, style, or shape object.


User-defined XML that is contained within a SolutionXML element and stored in one of the following containers: VisioDocument; the A, B, C, or D elements contained in a Scratch element; or the Value element contained in a User or Prop element.

Sparse instance

An instance shape (such as for a master that is a group) that does not have all its elements specified. Creating a sparse instance of a shape means specifying the top-level shape in the instance without listing its subshapes.

Trusted XML file

An XML for Visio file that contains a stamp, which is a processing instruction identifying the document as being unchanged since it was saved by Visio. The stamp allows Visio to skip some of the validation of a document when it is opened and is only present in files that have been saved by Visio.

Unknown XML

User-defined XML that can be contained within VisioDocument, DocumentSheet, PageSheet, Shape, and StyleSheet elements. This XML is not understood by Visio but is round-tripped with a Visio file.

Untrusted XML file

An XML file that follows the Visio schema, but has been created or edited outside of Visio. If an untrusted file does not carry a stamp (a processing instruction that identifies whether the document has changed since it was saved by Visio) or the file carries a stamp that indicates the file has been modified outside of Visio, Visio checks that the XML is well-formed and valid.

URN (Uniform Resource Name)

Identifies a persistent Internet resource. A URN can provide a mechanism for locating and retrieving a schema file that defines a particular namespace. While an ordinary URL could provide similar functionality, a URN is more robust and easier to manage for this purpose because a URN can refer to more than one URL.

Unlike URLs, URNs are not location-dependent.

A URN uniquely identifies a document just like an ISBN number uniquely identifies a book. You see "URN" in the tag that identifies the schema document.

Valid XML

An XML document with elements and attributes that match the logical structure and data types defined in a particular schema.

VDX (Visio Drawing XML Format)

A peer to the binary Visio drawing file format (.vsd).

Void cell

Cells that have no intrinsic result type and are intended to hold any type of result; for example, the A through D cells in a Scratch row.

VSX (Visio Stencil XML Format)

A peer to the binary Visio stencil format (.vss).

VTX (Visio Template XML Format)

A peer to the binary Visio template file format (.vst).

Well-formed XML

XML with accurate beginning and ending tags, and containment relationships; that is, the XML conforms to the Worldwide Web Consortium (W3C) XML specification.

XDR (XML Data-Reduced)

Form of a schema definition file supported by Microsoft Internet Explorer 5.0 and later.

XML (Extensible Markup Language)

Extensible Markup Language (XML) is a meta-markup language that provides a format for describing structured data. XML provides basic syntax; all other elements are defined as needed. Visio drawings, stencils, and templates can be saved in XML format with the file name extensions .vdx, .vsx, and .vtx, respectively.

XPath (XML Path Language)

The part of XSLT that defines access to data through the tag hierarchy by pattern matching and searching.

XSD (XML Schema Definition defined by W3C)

The later form of the Schema definition file. Not currently available for Visio, but will be available in future releases. Use XDR.

XSL (Extensible Stylesheet Language)

A language used to transform XML-based data into HTML or other presentation formats, for display in a Web browser. The transformation of XML into formats, such as HTML, is done in a declarative way, often making it easier and more accessible than through scripting. In addition, XSL uses XML as its syntax, freeing XML authors from having to learn another markup language.

XSLT (XSL Transformations)

A programming language that provides commands that transform XML into something else, for example, HTML or more XML.