Since 1972, the Wonca Classification Committee develops the instruments necessary to research in general practice. Its main realization, the International Classification of Primary Care (ICPC), is available in more than twenty languages and has reached its second edition. The Committee, that is a real research laboratory for methodology, has produced or validated other tools either in the field of outcome measures or in the field of severity indicators. After the publication of a Glossary of Family Practice, the Committee develops a real dictionary of the discipline. The history of that unremitting quest is related here.