Key:*:signed

The suffix *:signed=* is added to a key to indicate whether the property can be verified by reading a posted sign.

Rationale

One of OpenStreetMap's principles is verifiability: that an independent observer should be able to verify the information in OSM with some degree of effort. Physically signposted information is often considered the gold standard for verifiable information. However, signs are not infallible, and information such as names can be communicated through other means. Setting this key to no can be a disclaimer that no sign is present, saving a ground surveyor the effort of searching for a sign in vain.

Common variants

• collection_times:signed=*
• fire_hydrant:diameter:signed=*
• maxheight:signed=*
• maxweight:signed=*
• name:signed=*
• opening_hours:signed=*
• ref:signed=*

Software support

StreetComplete can add many of these keys. However, its developers have proposed to replace this suffix with a prefix.

These keys are not known to be widely used by data consumers, but SomeoneElse-style is an example of a renderer that differentiates unsigned names.

Alternatives

The undocumented key sign=* appears to be used for largely the same purpose. However, it is unable to differentiate between different properties of a feature being signed or unsigned simultaneously. The key unsigned=* has the same limitation but uses a double negative to indicate that something is signposted.

As an alternative to setting one of these keys to yes, you can map the location and contents of the sign itself as a node. Its tag would depend on the sign's function, for example:

• advertising=board
• advertising=sign
• tourism=information information=board
• tourism=information information=sign
• traffic_sign=*

A more rigorous practice is to record the precise source of the information using source=*. Some subkeys, such as source:opening_hours=*, have typical values that indicate the sign's location.

See also

• Proposed features/Replace *:signed with is_signed:*