Often shortened to “de minimis”, this Latin phrase means that the law does not take account of trifling matters, or matters of little or no value or importance.
In other words, there is a threshold beneath which the law, in all its intellectual might and procedural majesty, does not deign to concern itself. It is similar to the rule according to which, in a given situation, substantial compliance is regarded as sufficient.
By way of example (highlighted in bold): Miah v Secretary of State for the Home Department  EWCA Civ 261;  QB 35 per Stanley Burnton LJ:
“ I first of all point out that the ‘near-miss’ principle contended for is not the same as the de minimis principle. If a departure from a rule is truly de minimis, the rule is considered to have been complied with. The starting point for the ‘near-miss’ argument is that the rule has not been complied with. In the present case, the failure to satisfy the requirement of five years’ lawful residence as a work permit holder, by a period of some two months, was not de minimis.”