An artifact, document, diary, manuscript, autobiography, recording, or any other source of information that was created at the time under study. It serves as an original source of information about the topic.
Because it makes it easier for the person who is interested in hiring you to read, and you'll more likely be hired with a neat understandable letter.
Answer:
how am I supposed to know if I dont know the story ♂️ lil bit more words