2.1.1.2 mso-application

One XML processing instruction tag named mso-application MUST be specified as part of the form file. This XML processing instruction tag's attributes, as defined by the following attributes, specify which client application to use to open this form file.

Attribute	Description
Progid	Specifies what client application will open this form file. This MUST be set to "InfoPath.Document".
versionProgid	Specifies what client application version was used to create this form file. It MUST be set to "InfoPath.Document.2" or "InfoPath.Document.3"