원래 이름 기록: NTT, Inc.; The University of Tokyo

A plurality of IDs are presented by chipless RFID using an object shape as an ID. Provided is an ID tag for arranging in a row a plurality of elements selected from: a first element having a peak of a reflection intensity in a first direction and a second direction; a second element having the peak of the reflection intensity in the first direction and having no peak of the reflection intensity in the second direction; a third element having the peak of the reflection intensity in the second direction and having no peak of the reflection intensity in the first direction; and a fourth element having no peak of the reflection intensity in the first direction and the second direction.