There has been some confusion here between different senses of "Putonghua." So to clarify: article 19 of the constitution of the PRC says "The state promotes the nationwide use of Putonghua (common speech based on Beijing pronunciation)." Pursuant to this the government supported a huge project to create language standards close to Beijing usage, but deliberately not identical to any specific usage in Beijing. This went along with the character simplification and the creation of Hanyu Pinyin. These official standards are tested by the 普通話水平測試 and the HSK. Many jobs, especially in education and the media require some level on the 普通話水平測試. The standards have been lightly amended over time. I am asking about this official Putonghua. Numerous current and older dialects and usages called Putonghua in other contexts are not my concern now.
I am trying to find an official statement of the current standard, and I much prefer English for this (I expect it is a fairly long document). I am especially interested to know what words are officially given erhua. I am told some are, but not nearly so many as commonly get erhua in daily use in various parts of China.
I am not looking for help preparing for the HSK. That is widely available. I am trying to find the official standard.