What are the general guidelines for using symbols in S.I.?

unitsandmeasurement
cbse

#1

(i) The unit names should not start with a capital letter, e.g., Newton, Joule, Coulomb etc., however their symbols can be written with capital letter e.g., N, J, C etc.
(ii) Symbols cannot be used in plural form, they are used in singular form only.
(iii) No full stop should be put at the end of the symbol of the unit.
(iv) No space should be given between a prefix and symbol of a unit, e.g., km, /AS, cm etc.
(v) A prefix is not used alone,