On the final page of the New Outlook Form Region wizard, you can select standard message classes and type the names of custom message classes that you want to associate with the form region.

The standard message classes are not available if the form region is designed to replace the whole form or the default page of a form. You can specify standard message class names only for forms that add a new page to a form or that are appended to the bottom of a form. For more information, see How to: Add a Form Region to an Outlook Add-in Project.

To include one or more custom message classes, type their names in the Which custom message classes will display this form region? box.

The names that you type must comply with the following guidelines:

• Use the fully qualified message class name (for example: "IPM.Note.Contoso").

• Use semicolons to separate multiple message class names.

• Do not include standard Outlook message classes, such as "IPM.Note" or "IPM.Contact". Only include custom message classes, such as "IPM.Note.Contoso".

• Do not specify the base message class by itself (for example: "IPM").

• Do not exceed 256 characters for each message class name.

The New Outlook Form Region wizard validates the format of your input when you click Finish.

Note:
The New Outlook Form Region wizard does not verify that the message class names that you provide are correct or valid.

When you complete the wizard, the New Outlook Form Region wizard applies attributes to the form region class that contain the specified message class names. You can also apply these attributes manually.

You can associate a form region with an Outlook message class after you complete the New Outlook Form Region wizard. To do this, apply attributes to the form region factory class.

The following example shows two FormRegionMessageClassAttribute attributes that have been applied to a form region factory class named myFormRegion. The first attribute associates the form region with a standard message class for a mail message form. The second attribute associates the form region with a custom message class named IPM.Task.Contoso.

<Microsoft.Office.Tools.Outlook.FormRegionMessageClass(Microsoft.Office.Tools.Outlook.FormRegionMessageClassAttribute.Note)> _
<Microsoft.Office.Tools.Outlook.FormRegionMessageClass("IPM.Task.Contoso")> _
<Microsoft.Office.Tools.Outlook.FormRegionName("Trin_Outlook_FR_Attributes.FormRegion1")> _
Partial Public Class FormRegion1Factory

' Occurs before the form region is initialized.
' To prevent the form region from appearing, set e.Cancel to true.
' Use e.OutlookItem to get a reference to the current Outlook item.
    Private Sub FormRegion1Factory_FormRegionInitializing(ByVal sender As Object, ByVal e As Microsoft.Office.Tools.Outlook.FormRegionInitializingEventArgs) Handles Me.FormRegionInitializing

End Sub

[Microsoft.Office.Tools.Outlook.FormRegionMessageClass
    (Microsoft.Office.Tools.Outlook.FormRegionMessageClassAttribute.Note)]
[Microsoft.Office.Tools.Outlook.FormRegionMessageClass
    ("IPM.Task.Contoso")]
[Microsoft.Office.Tools.Outlook.FormRegionName
    ("Trin_Outlook_FR_Attributes.FormRegion1")]
public partial class FormRegion1Factory
{
    // Occurs before the form region is initialized.
    // To prevent the form region from appearing, set e.Cancel to true.
    // Use e.OutlookItem to get a reference to the current Outlook item.
    private void FormRegion1Factory_FormRegionInitializing(object sender, 
        Microsoft.Office.Tools.Outlook.FormRegionInitializingEventArgs e)
    {
    }
}

Attributes must comply with the following guidelines:

• For custom message classes, use the fully qualified message class name (for example: "IPM.Note.Contoso").

• Do not specify the base message class by itself (for example: "IPM").

• Do not exceed 256 characters for each message class name.

• Do not include the names of standard message classes if the form region replaces the whole form or the default page of a form. You can specify standard message class names only for forms that add a new page to a form or that are appended to the bottom of a form. For more information, see How to: Add a Form Region to an Outlook Add-in Project.

Visual Studio Tools for Office validates the format of the message class names when you build the project.

Note:
Visual Studio Tools for Office does not verify that the message class names that you provide are correct or valid.