What is the location of the nomenclature section in a scientific paper? I received this comment from a reviewer: “ It is better to add a nomenclature section with a list of all the used symbols and their meaning as example (DVB-T, DVB-S2, BCH, OSFBC, LDPC...), consequently the paper should be re-arranged eliminating all the definitions given in the sections”.

Are there any specific position for this section ?
The correct position for a nomenclature section is the location normally used by the journal in question. While as Paul suggests, the logical location for this should be at the start of the paper, in many journals, the nomenclature section is placed at the end, largely because it does not "look as good" to have the nomenclature section right on the first page (which is optically the "prime real estate" of the paper).