Referee's report by Max Born, on a paper 'The indefinite metric in relativistic quantum mechanics' by K J Le Couteur Sectional Committee: Mathematics No clear statement regarding publication in the 'Proceedings of the Royal Society of London'. Has not had time to study the paper well, in addition to not being familiar with the literature of the subject, and as such found the paper difficult to understand. The results are interesting, but the theories are probably only of temporary importance, 'clearing the path for the future'. Suggests the opinion be sought of 'an expert of the younger generation'. [Published in the 'Proceedings of the Royal Society of London'] Endorsed on recto as received 16 August 1948. [August 1948]