IOF control feature: depression

A hollow shape opening upward.

Also known as: Depression symbol orienteering, Control description depression

Maps & navigationSport & gamesStandard profile

Meanings

The IOF control description symbol for a depression, a hollow in the ground.

Officially standardisedVerified fact
Marks a depression, a hollow in the ground, as the feature carrying the control.
Contexts: Maps
Officially standardisedVerified fact
Inverts the knoll symbol exactly, so the system encodes ground rising and ground falling as one shape and its mirror.
Contexts: Maps

A curved shape opening upward, the inverse of the knoll's mound.

IdentityHigh confidence: High confidence because the identity is defined by a current official standard.
Historical originModerate confidence: Moderate confidence because the historical origin is documented in encyclopedic references, 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.
Visual matchHigh confidence: High confidence because the visual match is documented in encyclopedic references.

International Specification for Orienteering Maps (ISOM)
International Orienteering Federation · retrieved 2026-08-23
The IOF's mapping specification, published openly, governs the symbols on every internationally sanctioned orienteering map. The full text is NOT REPRODUCED here and has NOT BEEN READ in full; records cite it for the existence, issuing body and defined form of a mark. See docs/paywalled-standards.md.
IOF Control Descriptions
International Orienteering Federation · retrieved 2026-08-25
The IOF specification defining the pictorial control description symbols, the columns of the description sheet and the meaning of each symbol within its column. Cited for a symbol's identity and defined meaning. Records describe the notation and are not competition rules.

Last reviewed 2026-08-25

Meanings

The IOF control description symbol for a depression, a hollow in the ground.

Officially standardisedVerified fact

Marks a depression, a hollow in the ground, as the feature carrying the control.

Contexts: Maps

Officially standardisedVerified fact

Inverts the knoll symbol exactly, so the system encodes ground rising and ground falling as one shape and its mirror.

Contexts: Maps

Confidence

IdentityHigh confidence: High confidence because the identity is defined by a current official standard.
Historical originModerate confidence: Moderate confidence because the historical origin is documented in encyclopedic references, 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.
Visual matchHigh confidence: High confidence because the visual match is documented in encyclopedic references.

Sources

International Specification for Orienteering Maps (ISOM)
International Orienteering Federation · retrieved 2026-08-23
The IOF's mapping specification, published openly, governs the symbols on every internationally sanctioned orienteering map. The full text is NOT REPRODUCED here and has NOT BEEN READ in full; records cite it for the existence, issuing body and defined form of a mark. See docs/paywalled-standards.md.
IOF Control Descriptions
International Orienteering Federation · retrieved 2026-08-25
The IOF specification defining the pictorial control description symbols, the columns of the description sheet and the meaning of each symbol within its column. Cited for a symbol's identity and defined meaning. Records describe the notation and are not competition rules.

Last reviewed 2026-08-25