it has only open caveats. I'd suggest you to compare to this file https://www.cisco.com/web/software/282074295/141143/cucm-readme-1151su4-Rev3.pdf --huge difference
For 11.5 there is very good document above all bugs resolved are documented, but for 12.x just open caveats... I need to provide this client to compare and decide to which version to move, client wants to exclude upgrading of his all applications they use in Infrastr. , Most of their app are compatible with 11.5 but we don't have any info about 12.0. Can you please share Readme file for 12.x if you have it ?
The README is available with the ISO file, go to downloads, find the ISO file and hover over it to get it.
Please find the Read me for CUCM 12.0.1(SU1, SU2)