That is not what anyone ever calls NT releases.

Multiple point releases of NT have received multiple service packs. SPs are absolutely not equivalent to or interchangeable with SPs.

For reference, these are the version numbers of NT:

3.1 -- 3 SPs

3.5 -- 3 SPs

3.51 -- 5 SPs

4 -- 6 SPs

5 (Branded "Windows 2000") -- 4 SPs

5.1 (Branded "Windows XP", "Server 2003") -- 4 SPs

6 (Branded "Windows Vista", "Server 2008") -- 2 SPs

6.1 (Branded "Windows 7", "Server 2008 R2") -- 1 SP

6.2 (Branded "Windows 8", "Server 2012")

6.3 (Branded "Windows 8.1" "Server 2012 R2")

10 (Branded "Windows 10", "Server 2016", "Server 2019", "Server 2022"); 10 numbered build releases issued, then 4 datecoded ones; 14 in all.

11 (Branded "Windows 11"); 2 datecoded releases so far.

In other words, 7 versions of NT with a minor-version point-release so far, and in total 16 service packs for those point-releases which did not change the major or minor version number.

> 5.1 (Branded "Windows XP", "Server 2003") -- 4 SPs

5.1 was XP only, and it had 3 SPs. Windows Server 2003 was 5.2, and it had 2 SPs.

I sit corrected. :-)