Certain other non-SI units are still occasionally used. Some are important for the interpretation of older scientific texts. These are listed in Tables 9 and 10, but their use is not encouraged.

Table 9 deals with the relationship between CGS units and the SI, and lists those CGS units that were assigned special names. In the field of mechanics, the CGS system of units was built upon three quantities and the corresponding base units: the centimetre, the gram and the second. In the field of electricity and magnetism, units were expressed in terms of these three base units. Because this can be done in different ways, it led to the establishment of several different systems, for example, the CGS Electrostatic System, the CGS Electromagnetic System and the CGS Gaussian System. In these three last-mentioned systems, the system of quantities and the corresponding system of equations differ from those used with SI units.

Table 9. Derived CGS units with special names
(erg, dyne, poise, stokes, gauss, oersted, maxwell, stilb, phot, gal)

Table 10 lists units which are common in older texts. For current texts, it should be noted that if these units are used the advantages of the SI are lost. The relation of these units to the SI should be specified in every document in which they are used.

Table 10. Examples of other non-SI units
(curie, röntgen, rad, rem, X unit, gamma; jansky; fermi; metric carat; torr, standard atmosphere; calorie; micron)