Sentence:  The original charges, however, are made in what is called a "day book", where they are written one after another, in the order in which the transactions occur. During the hours of leisure, these charges are copied into another book, ... the account of each man being placed under his name. This book is called the "leger". The act of copying from the day book into the <WSD>leger</WSD> is called "posting". 
Meaning of the word marked with <WSD> tags:  A book for keeping notes, especially one for keeping accounting records; a record book, a register.