1. One of the questions raised in this petition for Special Leave to appeal to this Court is whether the failure to supply a copy of the Report of the Public Analyst within the period of 10 days stipulated by R.9(j) of the Prevention of Food Adulteration Rules, as it was in force at the relevant time-it may be noticed here that R.9 0) which was in force at the relevant time has since been omitted with effect from January 4, 1977-was fatal to a prosecution under the Prevention of Food Adulteration Act. Was R.9 0) mandatory or directory? There are no ready tests or invariable formula to determine whether a provision is mandatory or directory. The broad purpose of the statute is important. The object of the particular provision must be considered. The link between the two is most important. The weighing of the consequence of holding a provision to be mandatory or directory is vital and, more often than not, determinative of the very question whether the provision is mandatory or directory. Where the design of the statute is the avoidance or prevention of public mischief, but the enforcement of a particular provision literally to its letter will tend to defeat that design,