I heard that there's a way of knowing if the editor used in creating office documents, (excel,word,powrpoint,etc.) is pirated or legitimate just by inspecting the document.

What I know is, only the author name, creation and modification time is embedded inside the document including all that you can see form the details tab when you right click a document.

My question is, are there any hidden details, ( product code, activation used , activation status , etc.) that is being embedded inside any created document without the knowledge of the author, for the purpose of tracing the real author of the document and the legitimacy of the software that is used to create the document?

i heard that too
it is made visible in print , as small yellow dots
only some types of printers can do that , but it exists and its true