1. 行为准则;规则;法典;法规
    A code is a set of rules about how people should behave or about how something must be done.

    e.g. ...Article 159 of the Turkish Penal Code.
           《土耳其刑法法典》第159条
    e.g. ...local building codes.
           地方建筑法规

2. 密码;暗码;代码
    A code is a system of replacing the words in a message with other words or symbols, so that nobody can understand it unless they know the system.

    e.g. They used elaborate secret codes, as when the names of trees stood for letters...
           他们使用了复杂的暗号，比如用树的名称代表字母。
    e.g. If you can't remember your number, write it in code in a diary.
           如果记不住自己的号码，可以用代码记在日记簿里。

3. (邮政)编码;(电话)区号
    A code is a group of numbers or letters which is used to identify something, such as a postal address or part of a telephone system.

code的翻译

    e.g. Callers dialing the wrong area code will not get through.
           打电话的人如果拨错区号，就无法接通。

4. 信号;标记
    A code is any system of signs or symbols that has a meaning.

    e.g. It will need different microchips to reconvert the digital code back into normal TV signals.
           把数字信号重新转换回通常的电视信号需要另外的微芯片。

5. (遗传)密码
    The genetic code of a person, animal or plant is the information contained in DNA which determines the structure and function of cells, and the inherited characteristics of all living things.

    e.g. Scientists provided the key to understanding the genetic code that determines every bodily feature.
           科学家们找到了破解决定各种身体特征的遗传密码的密钥。

6. 把…编码(或编号)
    To code something means to give it a code or to mark it with its code.

    e.g. He devised a way of coding every statement uniquely...
           他设计了一种把每句话进行独特编码的方法。
    e.g. The machines were coded so we could tell them apart.
           机器都编了号，便于我们区分。

7. 编码
    Computer code is a system or language for expressing information and instructions in a form which can be understood by a computer.

8. see also: bar code;Highway Code;machine code;morse code;postcode;zip code