How to specify a category attribute in a UWP user element?

Question

In WPF, when creating a custom control, you can classify your custom properties in the Visual Studio / Blend properties window by adding the following attribute:

[Category("MyCustomProperties")]    <---------
public bool MyProp
{
    get { return (bool)GetValue(MyPropProperty); }
    set { SetValue(MyPropProperty, value); }
}

There is no CategoryAttribute attribute in the WinRT System.ComponentModel namespace.

How is this done on a universal Windows platform?