Printing Standards help to communicate expectations but also limitations between designer, prepress and printer.

They are based on traditional printing processes such as offset, gravure or newspaper printing.

Basically a printing standard such as ISO 12647-2 or ISO 15339 describe the result of a print using a best-practice machine setup.
These standards are created by ISO committees where industry experts work together to make the life of everyone in the printing industry easier.
The committee which creates most of the standards that are relevant to the printing industry is ISO TC130 where also people from MYIRO provide their expertise.

The resulting standards are published by ISO and have to be bought. But for daily work it is often not necessary to buy the standards and read them. 
There are a lot of industry organizations which publish information about these standards and the resulting best-practices free of charge.
Here we'd like to give you some hints where you can find useful information.