We remember and guard against forgetting,
for future times from past times!
A yearbook is a way of recording (a historical genre) that represents a temporal (more or less) detailed record of historical events.
The record of events each year in yearbooks begins with the words: "Flight ..." or "In summer ..." (that is, "Years ... (you and those)"), from which the name - yearbook originates, and the skill of writing a yearbook is called Yearbooking.
The analogies of the word letopis (synonyms) would be: chronicle, yearbook or annals.