When my social media team needed to refresh our accessibliity guidelines, we discovered the Microsoft corporate guidelines to be even more out of date. After meeting with Microsoft subject matter experts, we gladly accepted the challenge of updating accessibility guidelines for the entire company. We worked closely with the subject matter experts and stakeholders, and applied our own expertise, to create a newly-updated document in use across the entirety of Microsoft.
Note: These guidelines are proprietary information and can be discussed upon request.