With the widespread adoption of the International Classification of Diseases (ICD) in China's medical evaluation and healthcare payment systems, the importance of disease classification coding has become increasingly prominent, drawing considerable attention from the industry. As ICD is rapidly promoted and applied, various work methods have been developed, with it disagreements in understanding have emerged. Some medical institutions strictly require physicians to select clinical diagnoses from the ICD list of disease and surgical names. This practice undermines and even replaces the coding process conducted by the professional coders, leading to practical issues and affecting the data quality. This article analyzes these issues and proposes that the diagnoses entered by physicians on the first page of medical records are essentially disease nomenclature, while ICD codes represent classified diagnoses. These two elements have fundamentally different purposes andfunctions. It is recommended that physicians understand the requirements of ICD coding for clinical diagnosis documentation, revert to a medical-centric mindset, and accurately record disease diagnoses by using disease nomenclature. For the ICD-coded data, the key to high quality lies in strictly adhering to ICD classification rules and aligning with international standards. Professional medical record coders should be trained in health informatics, master international classification rules to fulfill their responsibilities, and ensure the accurate transformation of clinical diagnoses into ICD codes.