| Convention | Definition |
|---|---|
| [-] | If an option includes "[-]" as part of the definition, then the option can be used to enable or disable the feature. For example, the -c99[-] option can be used as -c99 (enable c99 support) or -c99- (disable c99 support). |
| [n] | Indicates that the value n in [] can be omitted or have various values. |
| Values in {} with vertical bars | Are used for option's version; for example, option -i{2|4|8} has these versions: -i2, -i4, -i8. |
| {n} | Indicates that option must include one of the fixed values for n. |
| Words in this style following an option | Indicate option's required argument(s). Arguments are separated by comma if more than one are required. |