Document.CompatibilityMode Property (Word)
Returns a Long that specifies the compatibility mode that Word 2010 uses when opening the document. Read-only.
When you open a document in Word 2010 that was created in a previous version of Word, Compatibility Mode is turned on. Compatibility Mode ensures that no new or enhanced features in Word 2010 are available while working with a document, so that people who edit the document using previous versions of Word will have full editing capabilities.
The following example shows how to check if a document is in full fidelity mode before using a new feature. In this case, if the document compatibility mode supports using content controls, then a check box content control is added to the document.