Start by entering a name in the first column. Then select link type (Zero length, Homobifunctional (same group at both ends of the linker) or heterobifunctional), Link from and Link to - all are set through drop-down boxes.
In the X-linker column you set the composition of the linker after linkage has taken place.
Non-linker you set the composition of the linker, e.g. a linker attached at one end but not the other, typically caused by hydrolysis of the non-linked end.
Red-linker: the composition of a reduced linker. Only relevant if the linker can be reduced and is symmetrical.
When in a composition field, you can click the 'Composition' button to use the composition calculator to enter the composition.
If you want to add analysis for disulfide linking, you enter
Link type: Zero length
Link from: Cysteine
Link to: Cysteine