British theatre-type route indicator

An illuminated letter or number beside a signal.

Also known as: Alphanumeric route indicator, Stencil route indicator

Engineering & technicalRoad & transportStandard profile

Meanings

A British indicator naming the route set by displaying a letter or figure rather than pointing towards it.

Officially standardisedVerified fact
Names the route a signal has been cleared for, by letter or figure, where too many routes diverge for an angled indicator to distinguish them.
Contexts: Public information
Officially standardisedVerified fact
Requires a driver to know what each letter means for that location, which is the cost of covering more routes than a geometric indicator can.
Contexts: Public information

A rectangular box beside or above the signal head displaying a single illuminated letter or figure.

IdentityHigh confidence: High confidence because the identity is defined by a current official standard, but only a single source has been found so far.
Historical originLow confidence: Low confidence because the historical origin is documented in encyclopedic references, but only a single source has been found so far, but early or supporting evidence is limited, but the regional or cultural match to this specific claim is not precise.
Current useHigh confidence: High confidence because the current use is defined by a current official standard, but only a single source has been found so far.
Visual matchModerate confidence: Moderate confidence because the visual match is documented in encyclopedic references, but only a single source has been found so far.

GERT8000 Rule Book, Signals, handsignals, indicators and signs
Rail Safety and Standards Board (RSSB), Great Britain · retrieved 2026-08-24
The British national rule book module covering signals, indicators and lineside signs. Cited for a signal's identity and its defined meaning on the Great Britain network. Records are descriptive; the Rule Book itself is the operating authority and is not reproduced here.

Last reviewed 2026-08-25

Meanings

A British indicator naming the route set by displaying a letter or figure rather than pointing towards it.

Officially standardisedVerified fact

Names the route a signal has been cleared for, by letter or figure, where too many routes diverge for an angled indicator to distinguish them.

Officially standardisedVerified fact

Requires a driver to know what each letter means for that location, which is the cost of covering more routes than a geometric indicator can.

Confidence

IdentityHigh confidence: High confidence because the identity is defined by a current official standard, but only a single source has been found so far.
Historical originLow confidence: Low confidence because the historical origin is documented in encyclopedic references, but only a single source has been found so far, but early or supporting evidence is limited, but the regional or cultural match to this specific claim is not precise.
Current useHigh confidence: High confidence because the current use is defined by a current official standard, but only a single source has been found so far.
Visual matchModerate confidence: Moderate confidence because the visual match is documented in encyclopedic references, but only a single source has been found so far.

Sources

GERT8000 Rule Book, Signals, handsignals, indicators and signs
Rail Safety and Standards Board (RSSB), Great Britain · retrieved 2026-08-24
The British national rule book module covering signals, indicators and lineside signs. Cited for a signal's identity and its defined meaning on the Great Britain network. Records are descriptive; the Rule Book itself is the operating authority and is not reproduced here.

Last reviewed 2026-08-25