ortho-, meta-, para- The positions of substituents are indicated by numbers except that o- (ortho), m- (meta), and p- (para) may be used in place of
1,2-, 1,3-, and 1,4-, respectively (cf. Rule A-12.3), for benzene derivatives.
This HTML reproduction of Sections A, B and C of IUPAC "Blue Book" is as close as possible to the
published version [see Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, Pergamon Press, Oxford, 1979.
Copyright 1979 IUPAC.] If you need to cite these rules please quote this reference as their source.
Published with permission of the IUPAC by Advanced Chemistry Development, Inc., www.acdlabs.com, +1(416)368-3435 tel, +1(416)368-5596 fax. For comments or suggestions please contact firstname.lastname@example.org