I tracked a lot of Boeing documents to establish requirements for our calibration procedures while I worked at Boeing. There was no one else like me in metrology who did that. They included tool drawings, engineering drawings, facilities documents, process specs, etc. Utilizing PSDS, Redars, Edcoms, Documentum, etc. I also tracked national and international standards via IHS (via an automatic notification system) . I proposed to management that we build out the calibration procedure index to have tie-ins not only to the software documents but to these other documents as well. This was to ensure that the calibration technicians always working to the latest revisions. When I left there were some procedures with out-of-date Boeing authoritative requirements (reference material) in them. I am not sure how far they got with it as I was working on it just before I retired. No one else had the same passion for the job as I did. I wish I was still at Boeing, as I now have a list of industry standards related to audio that I could have obtained for free like you can now.