Watch List notes:

BANKNOTES, Ireland, Currency Commission Irish Free State, £5 (4), 6 September 1938, serial no.32T 075749, 15 October 1940, serial no.48T 010526, war code letter "A", 8 July 1941, serial no.51T 068034, war code letter "C", 5 June 1942, serial no.59T 086618, war code letter "D", Lady Lavery at left, rev River Lagan mask, signed by Brennan and McElligott (B&C LTN15, LTN19). Third with 2mm tear in top edge, generally fine to about very fine. (4)
The war code letter was an extra security feature used to keep track of the Irish banknotes from the point of their production in England to their delivery in Ireland between September 1940 and the D-Day landings in 1944.

Estimate: £200-300