the sign convention described in the previous section was adopted at the IUPAC meeting in Stockholm in 1953 and is now accepted internationally.
Prior to this agreement, chemists did not always use the same convention, and this inconsistency was the cause of controversy and confusion in the development and routine use of electrochemistry.
Any sign convention must be based on expressing half-cell processes in a single way--either as oxidations or as reductions.
According to the IUPAC convention, the term "electrode potential" is reserved exclusively to describe half-reactions written as reductions.
There is no objection to the use of term "oxidation potential" to indicate a process written in the opposite sense, but it is not proper to refer to such a potential as an electrode potential.
The sign of an electrode potential is determined by the sign of the half-cell in question when it is coupled to a standard hydrogeneletrode.
When the half-cell of interest exhibits a positive potential versus the SHE, it will behave spontaneously as the cathode when the cell is discharging.
When the half-cell of interest is negative versus the SHE, it will behave spontaneously as the anode when the cell is discharging.