Wire segment identification letter

[retoocs]

If I am modifying wiring originally going from component A to component B, changing it to go from A to C back to B, how should the wire segment letter be designated? There are other segments before A and after B.

[NutLoose]

Anything in?

https://www.easa.europa.eu/en/document-library/easy-access-rules/online-publications/easy-access-rules-acceptable-means?page=17#_DxCrossRefBm9000072