Recall Codes are a paper note in Fallout 4.
Location[edit]
Obtained from X4-18 during The Battle of Bunker Hill.
Transcript[edit]
Synth Recall Codes:
B2-57 - Theta 9 3 Stratus
Y9-15 - Beta 7 7 Tempest
Z3-22 - Gamma 4-9 Typhoon
F6-33 - Delta 6 2 Arcus