What is the に doing in「略語は社内での使用に留(とど)めましょう。」?


This phrase is a heading in a business-Japanese book. Underneath, the book
talks about avoiding casual contracted words in the office and on phone calls.

From what I know about 留める(とどめる), which is a transitive verb, I would think
「... **を** 留めましょう」 would be correct here. Although I can find examples of
「...に留める」, I can't find any that, to me, would make sense here. What does
「...に留める」 mean in this context?




One way to understand it is to think that これを is omitted.

So verbosely, the sentence says

> 略語(について)は、これを社内での使用に留{とど}めましょう,

which literally means

> Regarding abbreviations, let's keep this to internal use.

* * *

It is fairly common to move objects to the front this way.

  * この本はもう読み終えた I finished reading this book.
  * 必要なものは買った I bought necessary things.

* * *

The famous [Article 9 of the Japanese
Constitution](https://ja.wikipedia.org/wiki/%E6%97%A5%E6%9C%AC%E5%9B%BD%E6%86%B2%E6%B3%95%E7%AC%AC9%E6%9D%A1)
has the following:

> 第九条 **日本国民は** 、正義と秩序を基調とする国際平和を誠実に希求し、国権の発動たる **戦争と、武力による威嚇又は武力の行使は**
> 、国際紛争を解決する手段としては、 **永久にこれを放棄する** 。 ②
> 前項の目的を達するため、陸海空軍その他の戦力は、これを保持しない。国の交戦権は、これを認めない。

A literal translation of the bold part would be

> The Japanese people, regarding war and threat or use of forces, renounce
> these forever.




One way to understand it is to think that これを is omitted.

So verbosely, the sentence says

> 略語(について)は、これを社内での使用に留{とど}めましょう,

which literally means

> Regarding abbreviations, let's keep this to internal use.

* * *

It is fairly common to move objects to the front this way.

  * この本はもう読み終えた I finished reading this book.
  * 必要なものは買った I bought necessary things.

* * *

The famous [Article 9 of the Japanese
Constitution](https://ja.wikipedia.org/wiki/%E6%97%A5%E6%9C%AC%E5%9B%BD%E6%86%B2%E6%B3%95%E7%AC%AC9%E6%9D%A1)
has the following:

> 第九条 **日本国民は** 、正義と秩序を基調とする国際平和を誠実に希求し、国権の発動たる **戦争と、武力による威嚇又は武力の行使は**
> 、国際紛争を解決する手段としては、 **永久にこれを放棄する** 。 ②
> 前項の目的を達するため、陸海空軍その他の戦力は、これを保持しない。国の交戦権は、これを認めない。

A literal translation of the bold part would be

> The Japanese people, regarding war and threat or use of forces, renounce
> these forever.

