Integrity
The coherence of a site’s ecological structure and function across its whole area that enables it to sustain the habitat, complex of habitats, and/or the levels of populations of the species for which it was designated.

Internationally important numbers (of birds)
One per cent or greater of either the world or European population of a species.

Invertebrate Site Register
A database of invertebrate species of conservation importance and an evaluation of sites. Notable ‘A ’ - known from 30 or fewer 10km squares. Notable ‘B ’ - known from 100 or fewer 10km squares.