Document Properties

Document properties are strings of metadata containing information about a document. The Author, Title, and Created Date are examples of document properties. Use Lexical Expressions > Document Properties to configure specific matches of document properties to unique values.

For example, you might want to detect Microsoft Word documents with the following document property stored in the metadata:

Author (property) : Sales Director (value)

Standard Document Property names

The Gateway uses standard property names to describe internal format names that are represented across different applications. For example, the Author of a document can be represented in different ways according to the application:

• MS Office as cp.creator (OPC) and Author(CDA)
• PDF as Author and creator
• LibreOffice as initial-creator and creator
• JPEG including XMP, EXIF and IPTC. For example, Artist and CameraOwnerName

Instead of configuring separate document properties for each internal format, in this example you can use the document property Author to match all.

Supported file formats You can apply document property matching to .docx, .xslx, .pptx, .pdf, .jpeg and LibreOffice file formats.

Property names in the Gateway do not necessarily match the names used by popular EXIF viewers.

Custom Document Property names

You can add custom document properties. This might be useful if the metadata you want to detect is not included in the standard list of Gateway document properties.

How do I...

• Example 1: Specify a custom document property and its matching value

  I want to create an expression list which specifies a custom property 'Classification' as 'Top Secret'.

  1. Click Policy > Lexical Expressions and select the Document Properties tab.
  2. Click New to create an expression list. Rename to Classified Categories.
  3. Click New to add expressions.

  4. Add the Property: Classification and the Value: Top Secret

     Values are not case sensitive. A Classification value: top secret would also be matched.

  5. Click Add.

  When you have configured a Document Properties expression list, you can configure an Analyze Properties content rule to detect the expressions it contains.

• Example 2: Apply the list to a content rule

  I want to create a content rule which detects and blocks any Microsoft Word document which has been categorized with the 'Classification' of 'Top Secret'.

  Create the expression list: Classified Categories containing the custom Property: Classification matched with the Value: Top Secret. See Example 1.

  Create an Analyze Properties content rule:

  1. Click Policy > Content Rules > New to create a content rule.
  2. Select Analyze Properties from the list of templates. Use the Overview section to rename the rule or add any relevant notes.
  3. Configure the What to Look For? actions Analyze Properties section.
  4. Select Classified Categories from the Expression list drop-down menu.
  5. Configure the Media Types to include Microsoft Word documents.
  6. Configure the What to Do? actions to block or hold the communication.

  7. Apply the configuration.

     The content rule can now be applied to a policy route.

• Example 3: Use standard document properties

  I want to detect and block Microsoft Excel documents created by (Author) 'Finance Director'.

  1. Use the Document Properties tab to create the expression list.

  2. Add the following document Properties and Values:

     • Property: Author, Value: Finance Director
  3. Create an Analyze Properties content rule.
  4. Configure the Analyze Properties section to include the expression list.
  5. Use the Media Types section to include Microsoft Excel documents.
  6. Configure the What to Do? actions to block or hold the communication.
  7. Apply the configuration.

Document Property Modifiers You can use a modifier (!) in an Analyze Properties content rule to match either: All document properties: Use a single ! character in the Property field. Everything except a selected document property: Use !PropertyName in the Property field.

String Matching in Values The Gateway performs precise string matching when searching for particular values. For example the value 42 will match 42 (and -42) but will not match 142, 42b or 420. You must enter an exact value to guarantee a value match. You cannot use wildcards or regular expressions as values. Boolean Values If your document property requires a Yes/No Value, use true or false respectively. Dates Date formats cannot be precisely matched. It is recommended that date values are avoided when creating document property expressions.