A memorandum is usually written on paper instead of on official letter paper with the theme of reminding people of the things listed in the memorandum.

撰写备忘录通常无须使用机关信笺而是写在普通白纸上，旨在便于对方回忆备忘录中所列举的事项名称及数字等。

youdao

Certainly. A letter must be sent out of the company and must be mailed or posted. A memorandum is a communication within an organization.

当然可以。信函必须从公司里送出去，要通过邮局邮寄，便函是一个单位内部的沟通形式。

youdao

A letter must be sent out of the company and must be mailed or posted. A memorandum is a communication within an organization.

信函必须从公司里送出去，要通过邮局邮寄，便函是一个单位内部的沟通形式。

youdao

The City, the University and Gigabit Squared have signed a Memorandum of Understanding and a Letter of Intent that allows Gigabit Squared to begin raising the capital needed to conduct engineering work and to build out the demonstration fiber network.

ENGADGET: Gigabit Squared heading high-speed fiber and wireless internet initiative in Seattle