"An officer who (a) authorises a search... shall make a record in writing (1) of the grounds for the search; and (2) of the nature of the evidence that was sought."
" The record of the search required by section 18(7) of the Act shall be made in the custody record, where there is one."
"When Parliament lays down a statutory requirement for the exercise of a legal authority it expects its authority to be obeyed down to the minutest detail."
"You must look at the subject matter, consider the importance of the provision that has been disregarded, and the relation of that provision to the general object intended to be secured by the Act, and upon a review of the case in that aspect decide whether the enactment is what is called imperative or only directory."
"Acts of Parliament conferring power on public authorities very commonly impose conditions about procedure, for example by requiring that a notice shall be served or that action shall be taken within a specified time or that the decision shall state reasons. If the authority fails to observe such a condition, is its action ultra vires? The answer depends upon whether the condition is held to be mandatory or directory. Non-observance of a mandatory condition is fatal to the validity of the action. But if the condition is held to be merely directory, its non-observance will not matter for this purpose. In other words, it is not every omission or defect which entails the drastic penalty of invalidity. The distinction is not quite so clear-cut as this suggests, since the same condition may be both mandatory and directory: mandatory as to substantial compliance, but directory as to precise compliance. Where, for example, a local authority were empowered to assess coast protection charges on landowners within six months but did so after twenty-three months, the delay was so excessive that there was total non-compliance with the condition, and the assessments were void; but had the excess been a few days only, they would probably have been valid. The court may readily find reasons for overlooking trivial or unimportant irregularities. Sometimes the legislation makes it plain what the effect of non-observance is to be. But more often it does not, and then the court must determine the question. This the court does by weighing the inconvenience of holding the condition ineffective against the inconvenience of insisting upon it rigidly. It is a question of construction, to be settled by looking at the whole scheme and purpose of the Act and by weighing the importance of the condition, the prejudice to private rights, and the claims of the public interest."