IDF Yahalom cop. Tag. Typically, each IDF unit (yehida) has its own shoulder tag. Shoulder tags consist of a long section and a tip, which can be one of four shapes: a circle (commands, directorates and air force units except anti-aircraft), a square (Golani Brigade), a diamond, or a shield-like shape (most common). Yahalom is a special elite combat engineering unit of the Israeli Engineering Corps of the Israel Defense Forces. The name "Yahalom" (Diamond in Hebrew) is an abbreviation of "Engineering Unit for Special Operations".