For one false note the 39 clues what do those letters in place of the page number signify?

LOOK TO INDIAFor one false note the 39 clues what do those letters in place of the page number signify?
dunno, but the you know the first book? after page 15-something, the numbers change. if you match them to letters, it spells,





ANNE CAHILL DID NOT DROWN