Officialとofficerは、どう違う？

ある契約書を訳していたとき、次のような一文がありました。

The appropriate company officials should review the tax return* carefully before an authorized officer signs and files it. （*納税申告書）

日頃からofficialと officerの違いは気になっていたので調べました。

調べた結果をざっとまとめると：
official:
意味　a person appointed or elected to an office or charged with certain duties, office-holder, office-bearer (ある仕事に任ぜられている人)

使用例　A company official responded to our request.

officer:
意味

1. a member of a police force
2. a person who has an important position in a company, organization, or government
3. a person who holds a commission in the armed forces
   （1.警官、2.企業・団体・政府の幹部、3.軍隊の将校）

使用例
The bylaws set out the positions of the corporate officers. Typically, corporations have as officers a president and/or chief executive officer (CEO), one or more vice-presidents, a secretary, and a treasurer.

official は一般的に広く「役人」を意味し、public/government/city officials などをよく見かけますが、スポーツの審判員の意味でも使われます。

• a football official, baseball officials
• Linesman is an official who assists a referee in a game (as football, tennis or hockey)

一方officer は軍隊や制服組のニュアンスが強いようです。

• military officer, police officer, ambulance officer

大体違いが分かったと思ったら、こんな記事を見つけてしまいました↓。

Ethics: Definitions of “Public Official” and “Public Officer”
《米》NCSL (National Conference of State Legislators) の関連記事より

Is a state legislator a public official? Is a state employee a public officer? And why does this matter? In many states, ethics laws are written to apply to “public officials” or “public officers.” The subtleties in defining these terms play a significant role in determining who and what offices are subject to state ethics regulations. Definition According to Black’s Law Dictionary a “public official” is “one who holds or is invested with a public office; a person elected or appointed to carry out some portion of a government’s sovereign powers.” “Public officer” is defined in a similar way.

つまり、publicが付くとどちらも「役人」の意味で使えるということですね。
言葉は生きものですね。きっちりと線引きはできません。