Stefan Sommarsjö

Microsoft Word is one of the most used word processing tools worldwide. Word files are saved in the .docx file format, which is an open standard for storing documents. The .docx format uses XML, or Extensible Markup Language, to store text, images, and formatting information in a structured way.

File and Folder Structure

A .docx file is a collection of files and folders that are zipped together into a single package. When you create a Word document and save it as a .docx file, Word creates a folder with several subfolders and files inside it. This folder is then zipped into a single file with the .docx extension.

The folder structure inside a .docx file looks like this:

• docProps: Contains XML files that store document properties, such as the title, author, and creation date.
• _rels: Contains XML files that define the relationships between the various parts of the document.
• word: Contains the main content of the document, including the text, images, and formatting information.
• document.xml: Contains the actual content of the document, stored in XML format.
• fontTable.xml: Contains information about the fonts used in the document.
• settings.xml: Contains settings for the document, such as page margins and header/footer information.
• styles.xml: Contains the styles used in the document, such as headings and paragraph styles.
• [Content_Types].xml: Defines the types of content that are included in the document.

XML Schema

The XML schema used to create and store .docx files is known as the Open Packaging Conventions (OPC) XML schema. This schema defines the structure of the .docx file and the relationships between its various parts.

The OPC schema uses a concept known as a package to represent a collection of related files and folders. A package is defined by an XML file called [Content_Types].xml, which lists the various content types that are included in the package. This allows different applications to understand the contents of the package and process it accordingly.

Each part of the package is defined by an XML file, which contains the actual content of the part. For example, the document.xml file contains the main content of the document, while the styles.xml file contains the styles used in the document.

Common XML File Errors

XML files can become corrupted due to a variety of reasons, such as hardware failure, software bugs, or user error. When an XML file becomes corrupt, it can cause the corresponding part of the .docx file to become unreadable, which can in turn cause the entire document to become corrupt and not easily recoverable.

Some common XML file errors that can cause a .docx file to become corrupt include:

• Invalid characters: XML files are sensitive to certain characters, such as angle brackets and ampersands. If these characters are not properly escaped or encoded, they can cause the file to become invalid.
• Missing or invalid tags: XML files must have a well-formed structure, with opening and closing tags that match each other. If a tag is missing or invalid, the file can become unreadable.
• Incorrect namespaces: XML files use namespaces to define the structure of the file. If the namespaces are incorrect, the file can become corrupt.
• Invalid XML syntax: XML files must adhere to a specific syntax, with proper nesting and formatting of elements. If the syntax is invalid, the file can become corrupt.

The structure of .docx files and the XML schema used to create and store them are critical components of the Microsoft Word document format. Understanding the file and folder structure, as well as the common XML file errors that can cause a .docx file to become corrupt, can help users avoid data loss and ensure the longevity of their documents. By taking proper precautions and using reliable tools, users can create and store .docx files that are both accessible and durable over time.

Example of a simple XML file in incorrect format:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<w:document xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main">
  <w:body>
    <w:p>
      <w:r>
        <w:t>Hello, World!
      </w:r>
    </w:p>
  </w:body>
</w:document>

In this example, the closing tag for the w:t element is missing. This results in an incorrectly formatted XML file, which will cause errors when trying to open or process the file.

To correct this error, we need to add the missing closing tag for the w:t element:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<w:document xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main">
  <w:body>
    <w:p>
      <w:r>
        <w:t>Hello, World!</w:t>
      </w:r>
    </w:p>
  </w:body>
</w:document>

Now the XML file is correctly formatted, with all elements properly closed.

If the error is a missing closing tag for a single element in a Word document saved in the Open XML format, it’s possible that you may still be able to open the document in Word.

In many cases, Word may be able to detect the error and attempt to correct the missing tag or ignore it. However, depending on the severity of the error and how it affects the overall structure of the document, the file may not be able to be opened or may be missing some content.

If the file can be opened but is missing content, you may need to manually edit the XML code to add the missing closing tag or correct any other errors that are preventing the document from being displayed correctly.

It’s always a clever idea to have backups of important documents, in case of file corruption or other issues that prevent the file from being opened or used correctly. Additionally, it’s important to regularly save and check the integrity of files to avoid potential data loss due to file corruption or other errors.