There are standard prefixes for multiples and submultiples of SI units, and these are shown in Table 2.3. For example, 1/1000 of an ampere is a milliampere, abbreviated as mA.
The orthodox use of SI permits only those units and multiples listed in Tables 2.1, 2.2, and 2.3, with the following two exceptions: degrees Celsius (°C) for temperature, and liter (L) for volume. The SI system bowed to the use of these exceptions in order for the numerical values of temperature and volume to appear in more convenient magnitudes. The relationship between degrees Celsius and Kelvin and between the liter and cubic meters are: