Dynamics AX 2012 R3 WMDP: "A potentially dangerous Request.Form value was detected from the client" (how to allow sending "<" symbol?)

Dynamics AX2012R3 Warehouse Mobile Device Portal, IIS 8

We need to scan existing barcodes containing "<" symbol.

validateRequest="false" and requestValidationMode="2.0" doesn't help. Run out of ideas. Please help!

Full error text when submitting a form:

A potentially dangerous Request.Form value was detected from the client (IC="<asdf").
Description: ASP.NET has detected data in the request that is potentially dangerous because it might include HTML markup or script. The data might represent an attempt to compromise the security of your application, such as a cross-site scripting attack. If this type of input is appropriate in your application, you can include code in a web page to explicitly allow it. For more information, see http://go.microsoft.com/fwlink/?LinkID=212874.

Exception Details: System.Web.HttpRequestValidationException: A potentially dangerous Request.Form value was detected from the client (IC="<asdf").

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[HttpRequestValidationException (0x80004005): A potentially dangerous Request.Form value was detected from the client (IC="<asdf").]
System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection) +324
System.Web.HttpRequest.ValidateHttpValueCollection(HttpValueCollection collection, RequestValidationSource requestCollection) +239
System.Web.HttpRequest.get_Form() +50
System.Web.HttpRequestWrapper.get_Form() +10
System.Web.Mvc.FormValueProvider..ctor(ControllerContext controllerContext) +36
System.Web.Mvc.FormValueProviderFactory.GetValueProvider(ControllerContext controllerContext) +32
System.Web.Mvc.<>c__DisplayClass6.<GetValueProvider>b__1(ValueProviderFactory factory) +34
System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +164
System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +87
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +387
System.Linq.Enumerable.ToList(IEnumerable`1 source) +54
System.Web.Mvc.ValueProviderFactoryCollection.GetValueProvider(ControllerContext controllerContext) +251
System.Web.Mvc.ControllerBase.get_ValueProvider() +30
System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +62
System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +105
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +311
System.Web.Mvc.Controller.ExecuteCore() +105
System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +42
System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__4() +31
System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +16
System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +10
System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +549
System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +132
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +163