What is the purpose of including the number of enclosures in a letter?

Including the number of enclosures in a letter serves the purpose of ensuring that the recipient is aware of everything that should accompany the correspondence. This practice is important for clear communication and helps to prevent misunderstandings regarding what materials have been sent. When the recipient sees the notation indicating the total number of enclosures, they can verify that all the expected documents or items are present upon receipt. This is particularly useful in formal or business contexts, where important documents may need to be referenced or examined, and it's crucial that nothing is missed.

While summarizing contents or highlighting important attachments are also important aspects of letter writing, their primary function is different from indicating enclosures. Enclosures are specifically about confirming what has been included with the letter, rather than summarizing or prioritizing the importance of those documents.