noun
visitors' book; guest register
A book or register where visitors, guests, or attendees write their names, often at formal events, temples, or exhibitions.
結婚式の受付で芳名録に名前を書いた。
I wrote my name in the guest register at the wedding reception.
芳名帳 is a similar term for a guest book or register, but 芳名録 often implies a more formal or bound volume.
Compound of 芳名 (ほうめい, 'honorable name') and 録 (ろく, 'record'). The reading ほうめい is a respectful term for someone's name, and 録 refers to a written record.