A method for generating a library of DNA-adaptor products from at least two DNA fragments to facilitate the identification of the fragments in a high throughput sequencing data genomic data analysis workflow after amplification and sequencing, said method comprising: (I) generating a pool of DNA-adaptors, wherein the adaptors differ from each other by their total lengths of at least 3 and at most L max nucleotides, wherein each adaptor comprises a constant termination subsequence TS of length L TS , L TS 3 nucleotides concatenated with a variable spacer subsequence, and wherein the variable spacer subsequence is truncated from a common constant, predefined nucleotide sequence (S) having a length of L S nucleotides, wherein L S is between 5 to 20 nucleotides; (II) ligating, in a reaction mixture, a first and a second adaptors from the pool of DNA-adaptors to each end of a first double-stranded DNA fragment to produce a first DNA-adaptor product, each adaptor comprising a plurality of double-stranded or partially double-stranded polynucleotides, each double-stranded or partially double-stranded polynucleotide comprising a spacer sequence on the double-stranded extremity of the adaptor, so that the first DNA-adaptor product may be characterized by a numerical code formed by the respective lengths ( L 1 , L 2 ) of the first and the second DNA-adaptor spacer sequences ( SS 1 , SS 2 ); (III) ligating, in the same reaction mixture, a third and a fourth adaptors from the pool of DNA-adaptors to each end of a second double-stranded DNA fragment to produce a second DNA-adaptor product, each adaptor comprising a plurality of double-stranded or partially double-stranded polynucleotides, each double-stranded or partially double-stranded polynucleotide comprising a spacer sequence on the double-stranded extremity of the adaptor, so that the second DNA-adaptor product may be characterized by a numerical code formed by the respective lengths ( L 3 , L 4 ) of the third and the fourth DNA-adaptor spacer sequences ( SS 3 , SS 4 ). (I) generating a pool of DNA-adaptors, wherein the adaptors differ from each other by their total lengths of at least 3 and at most L max nucleotides, wherein each adaptor comprises a constant termination subsequence TS of length L TS , L TS 3 nucleotides concatenated with a variable spacer subsequence, and wherein the variable spacer subsequence is truncated from a common constant, predefined nucleotide sequence (S) having a length of L S nucleotides, wherein L S is between 5 to 20 nucleotides; (II) ligating, in a reaction mixture, a first and a second adaptors from the pool of DNA-adaptors to each end of a first double-stranded DNA fragment to produce a first DNA-adaptor product, each adaptor comprising a plurality of double-stranded or partially double-stranded polynucleotides, each double-stranded or partially double-stranded polynucleotide comprising a spacer sequence on the double-stranded extremity of the adaptor, so that the first DNA-adaptor product may be characterized by a numerical code formed by the respective lengths ( L 1 , L 2 ) of the first and the second DNA-adaptor spacer sequences ( SS 1 , SS 2 ); (III) ligating, in the same reaction mixture, a third and a fourth adaptors from the pool of DNA-adaptors to each end of a second double-stranded DNA fragment to produce a second DNA-adaptor product, each adaptor comprising a plurality of double-stranded or partially double-stranded polynucleotides, each double-stranded or partially double-stranded polynucleotide comprising a spacer sequence on the double-stranded extremity of the adaptor, so that the second DNA-adaptor product may be characterized by a numerical code formed by the respective lengths ( L 3 , L 4 ) of the third and the fourth DNA-adaptor spacer sequences ( SS 3 , SS 4 ). <EOS>