A control symbol consists of a backslash followed by a single, nonalphabetic character. For example, ~ represents a nonbreaking space. Control symbols take no delimiters.

• 一个控制符号由一个反斜杠以及紧跟着它的一个简单的非字母的字符。例如，~代表一个不换行空格。控制字符不需要分隔符。