David Lack kept his papers in used quarto envelopes with a manuscript indication of the contents; these in turn were kept in cardboard filing-boxes whose labels were often defaced or faded. These have been rehoused in archival folders and boxes. The papers have been grouped by subject matter into a roughly chronological sequence. Almost all the notes were made on the back of typescript drafts (themselves often bearing manuscript corrections) of earlier articles, books or letters. The catalogue items refer to the manuscript notes; no attempt has been made to identify or collate the originals of the typescripts.

Correspondence referring to specific investigations was always kept with the relevant data. Many collaborators, including amateur ornithologists and members of the general public as well as professional colleagues, contributed data, observations and amendments to Lack's research and published work. Except for some items in shelfmarks MSS. 14992/27-28, all correspondents are indexed; where information of special value occurs in the correspondence, an indication is given in the appropriate entry in the catalogue.

Shelfmarks MSS. 14992/65-66 include 34 notebooks of observations made by Lack and his collaborators of migration movements monitored by radar at various R.A.F. stations. These notebooks have been cleared as unclassified material by the Ministry of Defence.

Titles and descriptions in inverted commas are those which appear on the manuscripts or related published work.

Unless otherwise stated, all work is in Lack's manuscript or typescript.