ACK. I scrolled through the large diff (thank you very much for this contribution!) with git diff --word-diff=plain and all the changes I saw made sense.

I'll let some of the other SSSD developers voice their opinion rather than merging a patch on my own on a Sunday, but I'm glad for these changes, thanks!

Sure, no problem.
For what it is worth, issue SSSD/sssd#3555 was the starter.

I am not sure about this one. Maybe it was caused by mass conversion with sed :-) "GNU/Linux MIT based KDC" sounds weird to me.

Wiki says Linux distributions

https://en.wikipedia.org/wiki/List_of_Linux_distributions

the same here

I think it is the same case as about "Linux" should be an adjective here. Therefore probably only Linx. (maybe linux)?

Correct me if I'm wrong. I am not English native speaker.

Really nice work.

I had few comments about Linux and GNU/Linux and I would appreciate a help/review from @sgallagh :-)

It was a deliberate change based on https://web.mit.edu/kerberos/krb5-devel/doc/mitK5features.html :)

Please, see first paragraph of https://en.wikipedia.org/wiki/Linux
and all of https://en.wikipedia.org/wiki/GNU/Linux_naming_controversy

I prefer to use "GNU/Linux" for the operating system and "Linux" only for the kernel.
Words and thinking are related. With GNU/Linux people get to know GNU (sadly most users don't) and it helps to differentiate, f.e. dependence on operating system or on kernel; think about "Debian GNU/kFreeBSD" or "Android".

Neither am I an English native speaker. :)
To me it seems to refer to the operating system, not the Linux kernel.

EDIT: The previous comments were added using browser. This comment was sent by email. Due to the hash-like email address I thought it would append to the previous comment for line 6 of users/ldap_with_ad.rst. Alas it did not.

I can see on that page.

Supported platforms / OS distributions:
* GNU/Linux: Debian x86_64/x86, Ubuntu x86_64/x86, RedHat x86_64/x86

But

Collection support to the KEYRING credential cache type on Linux Credential cache

It confirms my assuption whether it is used as a noun or as an addjective

But in this case "Linux" is neither kernel nor "OS". Therefore I shared link to wiki. The only page where I was able to find "GNU/Linux distribution" is surprisingly gnu.org.

But it is really a nitpick and i do not prefer any of those. It is just really uncommon to see it as an adjective.

[1] https://www.gnu.org/distros/free-distros.html

OK lets merge it :-)
If there are people who really do not like "GNU/Linux" as an adjective then they can send PR :-)