PropertyDefinition Stream Structure

Office 2013 and later

Last modified: July 23, 2011

Applies to: Outlook

A PropertyDefinition stream structure is an array of FieldDefinition stream structures that contain definitions for all user-defined fields in a Microsoft Outlook item, and data-binding settings for some built-in fields.

You can programmatically manipulate the PropertyDefinition stream structure. However, you can achieve similar results by using the Outlook Forms Designer and, in particular, the Properties dialog box for a data-bound control.

Field definitions in a PropertyDefinition stream structure can be one of two formats: PropDefV1 and PropDefV2. Outlook supports both PropDefV1 and PropDefV2. All field definitions in a single PropertyDefinition stream structure must be of the same format. For more information about how PropDefV1 and PropDefV2 differ, see FieldDefinition Stream Structure.

Data elements in this stream are stored in little-endian byte order, immediately following each other in the order specified below.

  • Version: WORD (2 bytes), the format of the field definitions in the PropertyDefinition stream structure. The following table shows the possible values.




    Format is PropDefV1.


    Format is PropDefV2.

  • FieldDefinitionCount: DWORD (4 bytes), the number of field definitions in this stream. This is the count of array elements in the FieldDefinitions data element.

  • FieldDefinitions: An array of FieldDefinition stream structures. The count of this array is equal to the FieldDefinitionCount data element.