What if we don't care about letter case, and only care about the actual characters themselves?

那么如果我们关心字母大小写，只关心实际字符本身呢？

youdao

And the next letter is 'E'—'E' is about expectations.

下一个字母是“E”，“E”是关于期望（expectations）的。

youdao

Don't worry about the letter—I'm sure it'll turn up.

别为那封信担心，我相信会找到的。

《牛津词典》

She sings about reading a love letter and wishing the writer were with her now.

VOA: special.2009.01.26

So you may take this course ultimately via pass-fail or letter grade and I am more than happy to chat with you about the implications and to sign any paper work such as the stack here that you might need.

你可能希望这门课采用及格-不及格分制或者分数制,我很乐意跟你聊下,两个打分制各自的含义,也可以帮你在这里签到。

哈佛公开课 - 计算机科学课程节选

Could you tell us about a person who wrote a recommendation letter for you?

你能给我们介绍一位给你写推荐信的人吗？

写推荐书的人 - SpeakingMax英语口语达人

In that light, my question about the letter seemed trivial and out of place.

FORBES: Getting Past A Communication Impasse

The Kremlin, reacting to reports about the letter, said there was no quid pro quo.

CNN: Obama downplays letter to Russia regarding nuclear Iran

Speaking about the letter Mrs Thompson told Mr Justice Tugendhart: "I was absolutely mortified".

BBC: Mark James and Jacqui Thompson