In the older photon physics options, where a quark content inside an electron is obtained by a numerical convolution, one does not have to make the distinction between valence and sea flavour. Thus any quark (antiquark) initiator leaves behind the matching antiquark (quark), and a gluon leaves behind a quark + antiquark pair. The relative quark flavour composition in the latter case is assumed proportional to among light flavours, i.e. into , into , and into . If one wanted to, one could also have chosen to represent the remnant by a single gluon.