What code is used for the description 'Signal Indicator Light'?

• A. H
• B. HE
• C. GK
• D. HG

Answer: (C)

In signaling maintenance naming, each equipment description is tied to a two-letter code. The first letter groups the item into the signaling family, while the second letter narrows the specific device type within that family. A device described as a “Signal Indicator Light” is a lamp-based indicator used at a signal to convey status to the train crew. In the standard code list, this description maps to the code GK, so GK uniquely identifies that indicator light. Using this code ensures your references, parts, and maintenance steps line up precisely with the described device. The other codes correspond to different signaling components, so they wouldn’t match the description of a signal indicator light.