I want to know the answer to the following question:
What was the name of the document that standardized Serbo-Croatian?
All the background I'm provided with is that "In the 20th century, Serbo-Croatian served as the official language of the Kingdom of Yugoslavia (when it was called "Serbo-Croato-Slovenian"), and later as one of the official languages of the Socialist Federal Republic of Yugoslavia.". Is that enough to answer the question?