Hi Patch
Many thanks for the response.
The screenshot on the MS fonts and how to see if no authorization is needed is great - is there by any chance, a compiled list available of all the fonts that includes the designer/foundry info, and the embeddability status? - so I can determine which are MS fonts and usable with no authorization, and which require further permission seeking.
Q. To clarify, so taking the font used is a MS font (‘Designer = Microsoft’ meaning no need to request authorization), and the application using it is not for personal/non commercial use - that application can be a non-windows application yes?
Looking again through the FaQ's, the statement around embedding: When can I use document embedding? with the answer in the FaQ being: ****
**'**If an application follows the rules and restrictions defined in the OpenType or TrueType specification, you can use it to embed Windows supplied fonts in any document file it creates. For example, Microsoft Word and PowerPoint follow the rules and restrictions, so you can use these applications to create documents (such as Word documents, PowerPoint decks and PDFs) that include embedded fonts.’
I can see the embedding flag in the screenshot you placed, but this statement mentions MS applications that follow the rules and restrictions, - Word, PPT listed, and PDF output from those.
Q. As above I guess, how does this apply to applications outside of MS creating PDF's with embedded/sub-setted fonts - is it purely down to the embedding flag status on the font?
Q. It would therefore be safe to assume that those permissions above need requesting from the non MS designer on fonts that are not Designer = Microsoft?
So while this is also for general knowledge of Windows supplied fonts, the font in particular here is SimSun, but the info page for that font from here: https://learn.microsoft.com/en-us/typography/font-list/?source=recommendations list the font as below:

You can see the designer section is N/A, however it lists the Copyright and Vendor - does this then class as the point you answered in Q2 - that for this font I would need permission/confirmation from them?
However they are not listed on this page as a vendor: https://learn.microsoft.com/en-us/typography/vendors/#z
Q. What would you advise here as to permitted usage? how to go about requesting info?
Thank you again for your reply, I hope you are able and willing to answer these new queries
Thanks
Noel