然后，在你的第一列空栏中使用不同4符号为4不同的信息类型做标记。

Then, use a simple system of symbols to mark off 4 different information types in the column space left in the margin.

youdao

其种类很多，但基本的理念是在变量名的开始添加一个标记以表示其类型（例如，所有无符号长型变量都以ul 开头）。

There are lots of flavors of this, but the basic idea is that you put a tag at the beginning of a variable name saying what type it is. (So all unsigned long variables begin with ul, etc.)

youdao

其种类很多，但基本的理念是在变量名的开始添加一个标记以表示其类型（例如，所有无符号长型变量都以ul 开头）。

There are lots of flavors of this, but the basic idea is that you put a tag at the beginning of a variable name saying what type it is. (So all unsigned long variables begin with ul, etc.)

youdao