Dog tags

Every soldier in the Colonial Fleet wears hexagonally shaped "dog tags" around their neck.

Sharon Valerii's identification tags

These identification tags presumably contain the rank, name, and serial number of the soldier, as well as their ship or troop assignment.

In the event of the soldier's death, dog tags on the soldier's body aid in identification, particularly if damage to the soldier's body renders the body difficult or impossible to identify. Soldiers retrieve the tags from a body if possible during combat if unable to return with the dead soldier's body, as did Chief Galen Tyrol for soldiers Tarn and Crashdown, for return to a superior officer later (Fragged).

Captain Kelly was the somber recipient of nearly 85 dog tags from dead Galactica crewmen trapped in the port flight pod when it was vented to space by order of Colonel Tigh to prevent a catastrophic ship explosion (Miniseries).

When Kara Thrace had to leave Samuel Anders to return to Galactica, she gave him her ID tags as a promise that she would return (The Farm).

Thrace is able to keep her promise (Lay Down Your Burdens, Part I).

Notes

• In "Exodus, Part I," Samuel Anders refers to Sharon Agathon's ID tags as "dog tags", establishing that this modern military term is also used in the BSG universe.