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The sequence listing should be comprehensive and include all of the necessary annotations so it should not provide details of the modified residue/s in the description only. The sequence listing should not rely on a reference to any external source of information, which includes a table in the description of the patent specification.
As you note, WIPO ST.26 strongly recommends that the sequence should contain the unmodified nucleotide (or if not possible variable ‘n’) and a modified base feature. If there is a specific modified nucleotide which is not listed in Part 2 of Annex I of ST.26, then there should be both:
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