Definition of "Remembrancer"

“Thank you. Tuesday evening, in four days’ time, Daedra West hosts a gathering, the venue yet to be announced. Possibly one of the guildhalls. Her guest list, so far, is interesting.” She looked at Lev. “The Remembrancer himself may be there. Lesser faces from the City. […]

2014, William Gibson, The Peripheral, G. P. Putnam's Sons, page 222

In particular, Harkaway told him about the unelected offices of the Lord Mayor and the City Remembrancer, who can be mistaken for figureheads but, in fact, have extensive powers.

2014 November 16, Ned Beauman, “William Gibson: ‘We always think of ourselves as the cream of creation’”, in The Guardian‎