(The image is from the Internet)

1. What is public opinion?
China's laws and regulations currently do not clearly record public opinion, but Article 48 of the Rules for the Implementation of the Patent Law provides:“Any person may, from the date of publication of an application for a patent for invention till the date of announcing the grant of the patent right, submit to the patent administration department of the State Council his or its observation with reasons, therefor, on the application which is not in conformity with the provisions of the Patent Law.”
At the same time, “Handling of Public Opinion” in Section 4.9, Chapter 8 of Part II of the Guidelines For Patent Examination further states: The observations submitted by anyone to the Patent Office on an invention application not in conformity with the provisions of the Patent Law shall be included in the application file, and the examiner shall take them into consideration in the course of the substantive examination. It is not necessary for the examiner to consider the observations submitted after the issuance of Notification to Grant Patent Right. The handling of the observation submitted by the public does not need to be notified to the public concerned.”
The above is the legal basis for preventing the patent application from being granted by submitting public opinion. According to the above regulations, we can know at least the following aspects of public opinion:
(1) Applicable patent types: invention patent;
(2) Timing of submission: after the invention patent application is published, but before the patent is granted;
(3) Who can submit: anyone;
(4) CNIPA's handling method: as a reference for the examiner's examination; will not notice its handling status.
2. The effect and advantages of public opinion
2.1 Reduce the probability of invention patent application being granted
If the evidence and reasons that prove that the invention patent application does not comply with the provisions of the Patent Law submitted in the public opinion are indeed feasible, the examiner will generally accept the evidence and grounds, and may issue an office action accordingly, or even eventually reject the invention patent application. 
2.2 Compared with the invalidation procedure, it is more concealed and cost-effective
Anyone may submit public opinion without providing detailed information or even anonymously, and applicants for corresponding invention patent applications will not receive notifications about the public opinion. Therefore, the identity of the requester who submits public opinion can be effectively hidden, avoiding a direct conflict with the patent applicant. 
In addition, there is no official fee for the submission of public opinion, therefore the required cost is lower. There will be no procedures such as oral proceedings and response similar to the patent invalidation procedure after submitting the public opinion, the entire process is relatively simple and economical. 
3. How to submit a public opinion
The submission of public opinion generally requires three steps: searching, drafting and submission. 
3.1 Searching
Searching the reference documents related to the target patent application is an important step in the submission of public opinion. If the reference documents searched are strongly related to the target patent application, the grant probability of the patent application will be effectively affected. 
3.2 Drafting
After obtaining appropriate reference documents, you can start drafting a public opinion. At present, there is no provision for the format and content of the public opinion. Generally, it can be written in the form of a request for patent invalidation or an observation in response to an office action. The public opinion shall contain at least the following:
Bibliographic information of the target patent application: basic information such as the application number and invention name;
Grounds: what specific provisions of the Patent Law or the Rules for the Implementation of the Patent Law does the patent application do not comply with, and why it does not comply;
Evidence: relevant evidence supporting the above grounds, such as reference documents. 
3.3 Submission
There are currently two ways of submitting public opinion. If the public opinion only contains an observation, you can submit it online; if there are other documents, you need to submit it in person or by mail.
4. Key points for the submission of public opinion
When submitting public opinion, in order to more effectively achieve the purpose of preventing the target patent application being granted, the following matters should be noted: 
4.1. Timing of submission
It is recommended submitting public opinion as early as possible, perfectly before the issue of the first office action, so that the examiner can fully consider the submitted opinion during the first examination, if the evidence and grounds submitted are strongly persuasive, it is more likely to be adopted, which is more conducive to achieving the requester’s goal. 
If the examiner has issued an office action, then the public opinion submitted at this time should judge the probability of the target patent application being granted and its possible amendment based on the content of the office action to determine the evidence and grounds in the public opinion, or whether public opinion is still required. If the reference document adopted by the examiner is more detrimental to the grant of the target patent application than its own comparison document, it may consider not submitting public opinion.
4.2. Accurate evidence and grounds
In the process of patent examination, the examiner usually searches only patent literature, journal and magazine literature and books to find reference documents, which has certain limitations in evidence collection. If the requester of the public opinion has a certain understanding of the technical field to which the target patent application belongs and can find other evidence that can affect the grant of the target patent application, the evidence is more persuasive and easier to be adopted by the examiner. The evidence and grounds in public opinion should mainly consider the impact on the novelty and inventive steps of the target patent application. In addition, the requester can also consider the reasons such as whether the claims are clear and whether they are supported by the description.
4.3. Active monitoring and timely adjustment
CNIPA does not notify the requester of the public opinion about its disposal situation. Therefore, after submitting the public opinion for the first time, the requester should continue to monitor the target patent application's examination process to see if the examiner has adopted the opinion. There is no limit on the number of submissions of public opinion, if not adopted, the requester can continue to submit a public opinion, and consider strengthening reasoning or adding new evidence accordingly. During the monitoring process, it’s also necessary to monitor the applicant's response. The requester can supplement the opinions or evidence in a targeted manner according to the applicant's opinion statement or amendment.
Patent rights are an effective means of competition in the development of technology or the economy. Use public opinion to launch an early attack on a competitor’s patent application, so as to effectively prevent its grant during the examination stage, and thus eliminate market competition risks early, avoiding conflicts with competitors in patent invalidation procedure. The process of public opinion is more concealed, with less cost and time, which is an effective and reasonable tactic.