The (German) Federal Association of Printing and Media (BVDM) is selling a huge compendium regarding the ISO 12647-7:2016 and other, but just in german language i guess:
ProzessStandard Offsetdruck
The PSO (Prozess Standardisation Offset) is not „just“ a manual for the industry, it is also important as a base for legal disputes regarding the measuring methods and tolerances, by conflicts after complaining (in this country).
This, also published by the BVDM (in english language too, currently a 2020 version in progress):
https://www.bvdm-online.de/fileadmin/Themen/T_F/R_H/MediaStandard_Print_2018.pdf
is a try by „extracting“ the PSO to convey between the printing industry and the customers (espescially the grafic people which are involved…)
shortly (Offset sheetfed):
Tolerances in Stock:
Solids (CMYK): Differences in Lab-values up to
DeltaE (1976?, not sure yet…)
5, if the paperwhite is under/equal DeltaE
3 regarding the used profile/characterisation/condition or Output Intention…
Tonevalue increase:
0-25%: +/-3
30-65%: +/-4
70-100%: +/-3
Spread:
30-65%: up to 5
For
Digital Proofing have a look at page 50 in the Mediastandard linked above
So compared with the art of printing in the eighties in the last century it is a remarkable developement and improvement, but today also called a „barn door“
(By the way: Take care with the table 18 down right on page 31 in the MediaStandard, I had asked the publisher about „the typical resolution 250ppi“ and their suggestion besides on the right regarding non-periodic screens:
Nobody did remember, who had written that and could be asked for…
)
Best
Ulrich