>>Again, No.
>>As I read it, if you specfy you own class derived from System.Web.Util.RequestValidator then you replace the default behaviour (which checks the RequestPathInvalidCharacters property) - although you could still call the base.IsValidRequestString() if it was useful.
>>
>>FWIW, unless you are yourself creating a request which would violate the default rules I'd leave well alone. If you *are* generating a genuine request that falls foul of the default then use the override to identify and allow it - otherwise just pass the validation operation to the base class.....
>
>Ok, I understand now.
>
>The goal here is to avoid having a situation like http://www.mydomain.com/& to be logged in the Event Viewer. As, this will make less verifications to make.
>
>Thus, I am trying to see if I can adjust the framework to take care of that automatically, and simply redirect to the domain, such as http://www.mydomain.com.
>
>I understand I need to put that somewhere:
>
>

><ConfigurationPropertyAttribute("requestValidationType", DefaultValue := "System.Web.Util.RequestValidator")> _
><StringValidatorAttribute(MinLength := )> _
>Public Property RequestValidationType As String
>	Get
>	Set
>End Property 
>

>
>In it, I need to define my own class name to validate. Then, I need to set up the class such as:
>
>

>    Public Class CustomRequestValidation
>        Inherits RequestValidator
>
>        Public Sub New()
>        End Sub
>
>        Protected Overloads Overrides Function IsValidRequestString(ByVal context As HttpContext, ByVal value As String, _
>         ByVal requestValidationSource__1 As RequestValidationSource, ByVal collectionKey As String, _
>         ByRef validationFailureIndex As Integer) As Boolean
>
>            ' Set a default value for the out parameter
>            validationFailureIndex = -1
>
>            ' This application does not use RawUrl directly so you can ignore the check
>            If requestValidationSource__1 = RequestValidationSource.RawUrl Then
>                Return True
>            End If
>
>            ' Allow the query-string key data to have a value that is formated like XML
>            If (requestValidationSource__1 = RequestValidationSource.QueryString) AndAlso (collectionKey = "data") Then
>
>                ' The query-string value "<example>1234</example>" is allowed
>                If value = "<example>1234</example>" Then
>                    validationFailureIndex = -1
>                    Return True
>                Else
>
>                    ' Leave any further checks to ASP.NET
>                    Return MyBase.IsValidRequestString(context, value, requestValidationSource__1, collectionKey, validationFailureIndex)
>
>                End If
>
>            Else
>
>                ' All other HTTP input checks are left to the base ASP.NET implementation.
>                Return MyBase.IsValidRequestString(context, value, requestValidationSource__1, collectionKey, validationFailureIndex)
>
>            End If
>
>        End Function
>
>    End Class
>

>
>...where all the code in it, up until the last Else, would be adjusted to verify for such possibiity and redirect to the domain.
>
>This class can go in my Global.vb. However, I am not sure where to drop the RequestValidationType property section.

You can specify the replacement validation in web.config:

<configuration>
  <system.web>
    <httpRuntime requestValidationType = "{namespace}.CustomRequestValidation,{assemblyname}"/>
  </system.web>
</configuration>