definiens: means Know -How which was first generated by either Party under an Fcab Discovery Program and/or a mAb2 Development Plan and/or Technical Development ( whenever it was undertaken ) which constitutes ( i ) improvements, modifications and enhancements to the inventions claimed ( either in issued claims or pending claims ) in t he Licensor Background Patents that exist as of the Effective Date, and such improvements, modifications and enhancements are covered by claims ( either in issued claims or pending claims ) of the Licensor Background Patents that exist as of the Effective Da te ( ii ) [ * * * ] ( iii ) [ * * * ] and ( iv ) [ * * * ] provided always that Platform Know -How does not include any Know -How which constitutes ( a ) the amino acid sequence of the antigen binding site and Fcab constant domain wherein such antigen binding site sequence conf ers specific binding of the Fcab to an Accepted Fcab Target or ( b ) the use of an Antibody and its sequence which has an antigen binding site in a constant domain wherein such sequence confers specific binding of the constant domain to an Accepted Fcab Targ et or ( c ) the manufacture or formulation ( or methods of manufacture or formulation ) of an Antibody and its sequence which has a binding site in a constant domain wherein such sequence confers specific binding to an Accepted Fcab Target or ( d ) the modificat ion of a native binding site within binding loops to a native antigen [ * * * ]