(7) If the accused having been previously convicted of any offence is liable, by reason of such previous conviction, to enhanced punishment, or to punishment of a different kind, for a subsequent offence, and it is intended to prove such previous conviction for the purpose of affecting the punishment which the Court may think fit to award for the subsequent offence, the fact, date and place of the previous conviction shall be stated in the charge. If such statement has been omitted, the Court may add it at any time before sentence is passed. Illustrations (a) A is charged with the murder of B. This equivalent to a statement that A's act fell within the definition of murder given in sections 299 and 300 of the Penal Code; that it did not fall within any of the general exceptions of the same Code; and that it did not fall within any of the five exceptions to section 300, or that, if it did fall within Exception 1, one or other of the three provisions to that exception apply to it. (b) A is charged, under section 326 of the Penal Code with voluntarily causing grievous hurt to B by means of an instrument for shooting. This is equivalent to a statement that the case was not provided for by section 335 of the Penal Code, and that the general exceptions did not apply to it. (c) A is accused of murder, cheating, theft, extortion, adultery or criminal intimidation, or using a false property-mark. The charge may state that A committed murder, or cheating, or theft, or extortion, or adultery, or criminal intimidation, or that he used a false property-mark, without reference to the definitions of those crimes contained in the Penal Code; but the sections under which the offence is punishable must, in each instance, be referred to in the charge. (d) A is charged, under section 184 of the Penal Code with intentionally obstructing a sale of property offered for sale by the lawful authority of a public servant. The charge should be in those words.