Sir,I read the article by Mathaiyan, et al.[1] with interest. The title suggests that omission is not potentially harmful. Omission in writing name of the patient, dose and dosage can lead to potential harm. The author has himself used omission errors as potentially harmful errors. The omission errors have been used for completely different context. The omission errors as defined by American Society of Health-System Pharmacists (ASHP) guidelines are “The failure to administer an ordered dose to a patient before the next scheduled dose.”[2] Similarly, the prescription errors as stated by author are caused due to omissions, wrong choice of drugs or the dose, brand name prescribing, inaccuracy in writing, and poor legibility. A reference has been given to justify this statement.[3] But the above-mentioned article defines the prescription errors as errors in act of writing. Wrong choice of drug is not a prescription error but a prescribing error or fault.[23] A standard definition as to what constitutes omission errors and prescription errors would have been beneficial.