using complementary overhangs and toehold sequences to generate a 3-way heteroduplex, ligate knick, and then remove barcode duplex

At first I thought this was about olympic figure skating, but after a bit of googling I think:

Complementary overhang - https://en.wikipedia.org/wiki/Sticky_and_blunt_ends

Toehold sequences: https://en.wikipedia.org/wiki/Toehold_mediated_strand_displa...

Ligate (ligase?) knick (nick?) - https://en.wikipedia.org/wiki/Nick_(DNA)

Barcode - https://en.wikipedia.org/wiki/DNA_barcoding

Heteroduplex - https://en.wikipedia.org/wiki/Heteroduplex