You may be thinking of the analog act info can be found here
http://www.legislation.nsw.gov.au/fragview/inforce/act+226+1985+sch.1+0+N
this is the part you are probably interested in.
Any substance that is an analogue of a drug prescribed in this Schedule, being a substance that has psychotropic properties, is not separately specified in this Schedule and is, in relation to the drug, any of the following:
(a) a structural isomer having the same constituent groups as the drug,
(b) a structural modification obtained in one or more of the following ways:
(i) the replacement of up to 2 carbocyclic or heterocyclic ring structures with different carbocyclic or heterocyclic ring structures,
(ii) the addition of hydrogen atoms to 1 or more unsaturated bonds,
(iii) the addition of 1 or more of the following groups having up to 6 carbon atoms in any alkyl residue, namely, alkoxy, cyclic diether, acyl, acyloxy, monoalkylamino and dialkylamino groups,
(iv) the addition of 1 or more of the following groups having up to 6 carbon atoms in the group and being attached to oxygen, namely, alkyl, alkenyl and alkynyl groups (for example, ester groups and ether groups),
(v) the addition of 1 or more of the following groups having up to 6 carbon atoms in the group and being attached to nitrogen, sulphur or carbon, namely, alkyl, alkenyl and alkynyl groups,
(vi) the addition of 1 or more of the following groups, namely, halogen, hydroxy, nitro and amino groups,
(vii) the replacement of 1 or more of the groups specified in subparagraphs (iii)–(vi) with 1 or more other groups so specified,
(viii) the conversion of a carboxyl or an ester group into an amide group.