The figure illustrates possible localizations of open reading frames (ORFs) in a fragment (shown only for the forward strand). ORFs are shown as grey bars, »▹«denotes stop codons, »|« indicates the position of translation initiation site candidates. ORFs that are related by a common stop codon are grouped and we refer to them as ORF-sets. The box symbolizes the fragment range. Everything that might be located outside the box is invisible to gene prediction algorithms. Further explanations are given in section »Methods«.