From OpenStreetMap Wiki
|pipeline = marker|
|Marker sticks and labels for underground pipelines|
|Used on these elements|
|Tools for this tag|
- ref=* unique identifier of the marker, usually consecutively numbered
- support=pole/wall_mounted/ground/pedestal describes where the marker plate is mounted. Use wall_mounted also if the marker is mounted on a fence.
- cover=cone/fin/roof specifies the shape of the cover on top of a pole.
- operator=* (optional)
- phone=* (optional)
- emergency_phone=* (optional)
- substance=* the type of medium transported by the pipeline.
- pipeline:ref=* since markers are often located in close vicinity to, but not directly on top of a pipeline, pipeline:ref=* links the marker to the pipeline. Use the same value as in the pipelines ref=* tag. If the marker is defined in a node of the way, it is not necessary to specify this tag.
- valve:ref=* if the marker points to a valve which is located at a distance, valve:ref=* links the marker to the valve. Use the same value as in the valves ref=* tag.
- measurement=* if the marker has some kind of measuring box/device attached, this tag describes the kind of measurement provided. Use yes if the type of measuring can not be determined.
- position=left;right;distance;heading holds the position information (in meters) as listed on the marker. This position defines a point through which the pipeline is supposed to run. If a value is not specified on the marker plate, do not use this tag. heading is optional. It describes the direction the marker is facing in degrees (0 .. 360). May be measured by a compass, but is usually also stored as EXIF value in pictures taken by modern smartphones (don't forget to subtract 180°).
- left: distance from the marker to the left
- right: distance from the marker to the right. Usually, just left OR right is defined.
- distance: distance from the marker in direction to the position of the viewer (in front of the marker)
|Marker of gas pipeline in Mallorca|
|Marker of gas pipeline in Mallorca with two measuring points|
|Marker of the WAG pipeline, mounted on a pole, with roof cover #49.|
|Marker of the West 4 pipeline, mounted on a pole, fin cover.|
|A Measuring Point of the West 4 pipeline.|
|Cone shaped cover with measuring point, liquid natural gas.|
|A (very old) marker stone located on the ground.|
|Marker on a pedestal, France.|