When correcting a patent, you are required to use a correction notice. It only implements the correction of the patent content and cannot state personal opinions. During the patent correction, if you feel that there is someone personal, you can use a statement of opinion when explaining to the examiner. , the purpose is to state your personal opinions, or to state content that cannot be expressed in the amendment, so that the examiner can understand your intention to revise, thereby improving the approval rate of your patent application. Therefore, when correcting a patent, a correction letter must be used, and a statement of opinion is used only when necessary. Of course, the statement of opinion can also be used in other situations. For example, when the examiner questions your patent, you can use the statement of opinion to eliminate the examiner's doubts, etc.
In short, the supplementary letter and the statement of opinion can be used in conjunction with each other, or they can be used separately. One focuses on the modification of the patent, and the other focuses on the statement of personal opinions.