Sometime ago the question Ms-RL - Explanation needed was posted. The only answer given relating to section 3A was:-
3(A) Reciprocal Grants- For any file you distribute that contains code from the software (in source code or binary format), you must provide recipients the source code to that file along with a copy of this license, which license will govern that file. You may license other files that are entirely your own work and do not contain code from the software under any terms you choose.
Translation: For each file that uses files under the Ms-RL, you need to provide the source and a copy of the license.
What is not clear to me is the definition of the word file. If I make use of a DLL licensed under Ms-RL (such as a visual component/control) and I ship my DLL/EXE along with their DLL and their source code is that sufficient to satisfy the license? If I now zip the files or compose an MSI do I now have to include my source code too as the zip/MSI file contains the binary of their DLL?
If you're shipping the component itself, just make sure that the source of it is made available "somewhere" and it's properly defined the license being used (in this case the Ms-RL), just a txt somewhere saying "the component can be found at xxx"
It's not a viral license so using this doesn't affect the rest of your project