The linear object identification tag 10 can be attached to and detached from a linear object 40. This tag has a clip body having a pair of clip parts 1a, 1b openably joined to a base part 6, and a holding part 8, 9 which holds the linear object 40 inside the linear object identification tag and is formed on an inner face of at least one of the clip parts 1a, 1b. Installation is thus efficiently performed by simply inserting the linear object 40 through an aperture part. 7. An installation tool (FIGS. 12, 13) with guide parts (22c, 22d) for opening the clip parts (1a, 1b) as they are slid along the tool is disclosed. In another embodiment, labels (719, 720) may be applied to plugs (75) and receptacle (72) and an instrument (722) with optical readers (723, 724) used to read codes on the labels.