This document describes a data model and XML syntax for representing information about points of interest (POI) on the World Wide Web.


In general terms, a "point of interest" is a location about which information is available. A POI can be as simple as a set of coordinates and an identifier, or more complex such as a three dimensional model of a building with names in various languages, information about open and closed hours, and a civic address. POI data has many uses including augmented reality browsers, location-based social networking games, geocaching, mapping, and navigation systems.

POI data has traditionally been exchanged in proprietary formats via various transports. This specification defines a flexible, lightweight, extensible POI data model, and one normative syntax for the data model. This will enable content publishers to effectively describe and efficiently serve and exchange POI data. In addition to the data model and format, this specification includes best practices for how to organize and serve POIs on the Web.

To achieve these goals, this document describes a generic data model and one normative format. This format is based on XML and is likely insufficient to cover all POI use cases, therefore, it is expected that the data model will be mapped to other formats, such as JSON, GML, RDF, GeoRSS, or HTML.


The term points of interest is used in a broad sense in this specification to refer to a loosely coupled and inter-related set of terms: locations, POIs and places.

This section is primarily based on the wiki home page definition of POI.

The term location is used to refer to a geographical construct, a physically fixed point, typically on the surface of the Earth (relative to WGS-84), though locations can be relative to another coordinate system. Locations can be a single point, a centroid, a minimum bounding rectangle, or a set of vectors. A location should be persistent over time and does not change.

OGC has suggested the following changes to the definition of location: FYI, Point of Interest is defined in the OGC Open Location Services standard as:
A location (with a fixed position) where one can find a place, product or service, typically identified by name rather than by address and characterized by type, which may be used as a reference point or a target in a location based service request, e.g., as the destination of a route.
The definition for “Location” should be harmonized with ISO standards terms and definitions. Also, a specified coordinate reference system (WGS 84) should not be mentioned in a definition. The specification and handling of CRS should be later in the document. So, the definition of Location becomes:
Location: Identifiable geographic place [[ISO19112]]. Typically a location is a physically fixed point, typically on the surface of the Earth, though locations can be relative to other, non-earth centric coordinate reference systems. Locations can be a single point, a centroid, a minimum bounding rectangle, or a set of vectors. A location should be persistent over time and does not change.

Points of Interest
Unlike the term location, the term POI is a human construct. POIs describe information about locations such as name, category, unique identifier, or civic address.
A place is also a human construct which typically has a coarse level of spatial granularity. Places are generally larger scale administrative constructs, either informally or formally defined. Countries, states, counties, districts, neighborhoods and postal codes or telephone area codes are all places. Places are also informally or colloquially defined, such as the Home Counties in the United Kingdom and the Bay Area in the United States.
Places have spatial relationships; with parents, children, adjacencies and contained by semantics. Places also have the same attribute set as POIs, although with differing interpretations based on scale; for example, the address of a Place or its URI would refer to the address of the administrative or governing body of the place.
A place typically contains multiple POIs and can also be coterminous with a POI. In the former case, a place, such as a city or a neighborhood, will contain multiple POIs. In the latter case, a place and a POI will occupy the same position and extent, such as in the case of Yellowstone National Park, which is both a Place and a POI.
The term primitive refers to the basic components of a POI. For example, a POI could be a collection of location and category primitives.
The term coordinate refers to one of a sequence of n numbers designating the position of a point in n-dimensional space [[ISO19111]].
Coordinate Reference System
The term coordinate reference system refers to a coordinate system that is related to an object by a datum [[ISO19111]].
Coordinate System
The term coordinate system refers to a set of mathematical rules for specifying how coordinates are to be assigned to points [[ISO19111]].
The term datum refers to a parameter or set of parameters that define the position of the origin, the scale, and the orientation of a coordinate system [[ISO19111]].
The term geolocation refers to the identification of the real world geographic location of an object.
The term point refers to a 0-dimensional geometric primitive, representing a position [[ISO19107]].
The term position refers to a data type that describes a point or geometry potentially occupied by an object or person [[ISO19133]].
The term route refers to a sequence of links and / or partial links that describe a path, usually between two positions, within a network [[ISO19133]].

POI Data Model

The following primitives can be combined to represent a POI.


Geo-references are used a lot and were difficult to introduce just in the middle of the location primitive, so it got a promotion, even though it only appears in the location primitive.

A geo-reference is a reference to a location. A geo-reference can represent location in a variety of ways, such as the geospatial coordinates for the center of the POI, a civic address, an area (simple bounding box, or a polygon, or a 3d object), relative to a particular map or other geo-reference or undetermined. Geo-references are used in the location primitive.

A geo-reference is of one of the following types:


The Center geo-reference locates the center point of the POI. This type is largely used for display purposes.

Name Required Details
Coordinates required
System optional If not specified WGS 84 is assumed
Longitude required
Latitude required
Altitude optionalDefines the height in meters above or below sea level

OGC has recommended the term geolocation instead of georeference:
Georeference – While geo-reference is a valid term, geo-reference typically indicates that a geometry or an image has coordinate reference system metadata. The suggested term is geolocation as this term is used extensively in other standards work, including the work of the W3C.

Navigation Point

A Navigation Point geo-reference is to a point that is the logical destination for routing. For example, this may be a reference to the entrance of parking lot POI.

Name Required Details

Note:Support for addresses in the XML syntax has been dropped for the FPWD, but reminds here in the data model.

An Address geo-reference is a civic address, such as a mailing address or a street address.

Name Required Details
Country requiredISO country code (ISO 3166-1 alpha-3 country code)
Language requiredxml:lang Language Code
Street optional Can contain a variable mix of house number prefix, suffix, street base name and or street type
Floor optional +/- number
Suite optional
Region optionalRepeating: can contain a variable mix of administrative regions, neighborhood, city, state, etc.
Postal-code optional

This is our first reference to language tags, should we use ISO 3166-1 or BCP 47/IETF RFC 5646? It's been suggested to use xmllang, but do we need to specify this in the data model? Probably, as we do want interchangeability between formats.


This section needs reworking. Within the XML syntax there's a notion of a list of points, as well as a point type that is reused. In the Wiki draft Routes and Areas both have point lists, we should extract the point list concept out so it can be shared.

Optional. Represents routes and traces.

Required. Repeating for a directed linked list of points
Required. One of : Start/End/way point

An Area geo-reference represents a line-bounded area. The area is described by an ordered list of coordinates, where the first and last are the same.

I changed this one a bit, instead of introducing Points, I just made it have Coordinates, and mention that it is an ordered list of them where the first and last are the same. I figure the ordering can occur however such things happen in desired syntax (XML could be as they appear in document order or with an 'order' attribute, JSON may represent it as an array,etc)

Name Required Details
CoordinatesrequiredAn ordered list of Coordinates, minimum of three, first and last must be the same.

The following paragraphs are adapted from Christine Perey's email. Parts of this are related to collections of POIs/objects and is thus also related to ISSUE-28. This section needs serious attention.

The Object primitive provides a rich and flexible description of an object, which decouples the description of an object from where it is located.

An Object MAY have one location at a (temporary-duration undefined) specific point in time but does not have one fixed point over time.

An Object of Interest can be a parent to other Objects each with its own description to allow for the representation of complex objects that are the aggregate of a collection of Objects (a car, boat, or airplane).

It should not be inferred that each of the elements within the object primitive are not spatially synonymous, but do refer to the same object.

Represents a 3D object, building, etc.

Name Required Details

An Undetermined geo-reference represents a location that as of yet is undetermined. This can be used to describe a Place prior to the final location being resolved.

There are no members for an Undetermined geo-reference.


I made relative a member of geo-reference rather than a sub-member of the map geo-reference, as it seems useful outside of the map scope

A Relative geo-reference is described in terms of distance from and bearing to another location.

Name Required Details
Relative-Location-Object requiredID or location object (ID) this relative reference refers to
Relative heightoptional

Map georeference type has been dropped from the FPWD until it is better understood.


The location primitive provides a rich and flexible description of the location of a POI. A location is a required part of a POI.

Name Required Details
IdentifierrequiredA unique identifier for this location.
Geo-referencerequiredA reference to the actual location

I didn't follow the definition of a location identifier, so details were removed

Relationship primitive

The relationship primitive establishes 1-to-1 or 1-to-many relationships between POIs.

A relationship may be one of the following:

A POI which is entirely contained within another POI, e.g. a POI describing a store may state that it is contained within a shopping mall
A POI which entirely contains another POI, e.g. a POI describing a mall may state that it contains POIs for each store that is within the mall
A POI which is physically adjacent to another POI, e.g. a POI representing a store within a mall may state that it is next door to another POI which represents the store next door

Need more relationship types

Should the details of the various relationship types themselves be in this section? Assuming yes for now







string primitive

Dropped per our discussion at f2f

Label primitive

POIs may have zero or more label primitives which represent a human readable label.

At F2F2 we decided to rename the name primitive to "label", and to allow labels to be marked as primary for each language represented.

ID primitive

POI must have an "id" primitive. It unambiguously identifies a POI within a particular implementation.

At F2F2 we discussed using URI fragments as IDs, as in XML. Using XML Base we could build a full URI that could then be used to identify the entire POI.

Categorization primitive

POI MAY have a "categorization" primitive, with one or more category identifiers.


meta data primitive

Todo. We haven't decided how this would work, and why this wouldn't just be covered by our extensibility story. Please see: ISSUE-18.

Time primitive

POI MAY have one or more time primitives that represent an individual point in time, a span of time, or a recurring time or time span.

XML Syntax

Even more so than the rest of this document, this section is a straw man proposal, so please treat it as such!

This section describes an XML syntax to represent the data model.

XML Notation

The following data types are from XML Schema, Part 2: Datatypes [XMLSCHEMA11-2]. The meanings are provided here as a convenience, for more complete information refer to the XML Schema, Part 2: Datatypes Recommendation.

Notation Meaning
booleanhas the ·value space· required to support the mathematical concept of binary-valued logic: {true, false}
decimala subset of the real numbers, which can be represented by decimal numerals
floatpatterned after the IEEE single-precision 32-bit floating point type [IEEE 754-1985].
doubleatterned after the IEEE double-precision 64-bit floating point type [IEEE 754-1985].
durationrepresents a duration of time.
dateTime may be viewed as objects with integer-valued year, month, day, hour and minute properties, a decimal-valued second property, and a boolean timezoned property. Each such object also has one decimal-valued method or computed property, timeOnTimeline, whose value is always a decimal number; the values are dimensioned in seconds, the integer 0 is 0001-01-01T00:00:00 and the value of timeOnTimeline for other dateTime values is computed using the Gregorian algorithm as modified for leap-seconds
timerepresents an instant of time that recurs every day
date consists of top-open intervals of exactly one day in length on the timelines of dateTime, beginning on the beginning moment of each day (in each timezone), i.e. '00:00:00', up to but not including '24:00:00' (which is identical with '00:00:00' of the next day)
gYearMonthrepresents a specific gregorian month in a specific gregorian year.
gYearrepresents a gregorian calendar year
gMonthDaya gregorian date that recurs, specifically a day of the year such as the third of May
gDaya gregorian day that recurs, specifically a day of the month such as the 5th of the month
gMonthgregorian month that recurs every year
anyURIrepresents a Uniform Resource Identifier Reference (URI). An anyURI value can be absolute or relative, and may have an optional fragment identifie

We need to figure out: xml id/xml:base, xml:lang, units of measurement

<pois> element

The root element for an POI in XML syntax is the pois element. The <pois> element MUST contain one or more <poi> elements.


The <pois> element has TBD attributes.

We may not allow for collections of POIs, in which case there will be no pois element.

The pois element could have attributes such as xml:lang and an id, but is there a case for more? What's the right way to represent text-wise that lang and id's can be on all elements?

<poi> element

The <poi> element encompasses all information about a single POI. The <poi> element MUST contain one or more <location> elements, and MAY contain one or more <label> and <category> elements.


see above note in the <pois> element about lang and id

Representing coordinates

Many of the elements described below rely on a coordinates as attributes. In the interest of not repeating the definition, the following attributes are inferred whenever the coordinate attributes are referenced below.

NameRequiredTypeDefault valueDetails
srsnameoptionalanyURIurn:ogc:def:crs:EPSG:6.6:4326A URN as defined in OGC Definition identifier URNs in OGC namespace [OGC-07-092r1] of the geodetic system to which the latitude and longitude and altitude are relative
altitudeoptionalnumber?? sea level relative to system?

Is there an official geode tagging scheme, e.g. "wgs84", or "etrs89"? Apparently yes:
Now tracked as issue: ISSUE-21.
How does this effect the altitude attribute?

<point> element

The <point> element is used in many different geo-reference types below. It represents a single set of coordinates, and can be ordered relative to other <point> elements within the parent element via the order attribute.

The <point> element has no character data.


The <point> element uses the coordinate attributes, and an order attribute.

NameRequiredTypeDefault valueDetails
orderoptionalunsigned-numberNoneApplies only when a list of points is needed. Within the parent element containing the point list, there must be one <point> with the order attribute set to '0', other <point> element's order attribute MUST be unique and contiguous integers. Each point element within a point list MUST have the order attribute set.

Do we want to use an order attribute? Document order? A single attribute with a list of comma separated coordinates?
Now tracked as: ISSUE-19: how should we represent points? and a related issue: ISSUE-36: do we want to rely on document order?.

<location> element

The <location> element contains one or more geo-references elements (see below), and has no attributes or character data.

Geo-reference elements

The following elements are the XML mapping for the geo-references outlined in the data model. Geo-references are used only with in the <location> element.

<center> element

The <center> element has no character data, and only the coordinate attributes.

<address> element

Representing addresses is a tricky business, see Geolocation WG and IETF geopriv.
As such address will be moved to TBD in this draft. This issue is now tracked as ISSUE-40

Should there be a way to assign languages to addresses or parts of addresses?

<navigation-point> element

The <navigation-point> element has no character data and only the coordinate attributes.

<area> element

The <area> element MUST contain three or more <point> elements. The first and last points in an area point list must have the same latitude, longitude and altitude. The area element has no attributes.

<object> element

This geo-reference hasn't been written yet

Name Required TypeDefault value
<undetermined> element

The <undetermined> element has no character data and no attributes.

<relative> element

The <relative> element has no character data.

NameRequiredTypeDefault valueDetails
location-idrequiredidref (not really, more of a xsd:anyURI as it can be external too)NoneThe fragment identifier or URI of the object to which this location is relative.
distance-fromrequiredintegerNoneThe distance this object is from the object referred to in the location-id attribute
bearing-torequireddecimalNone?? radians? degrees?

<map> element

Map georeference type has been dropped from the FPWD until it is better understood, so the map element has been dropped as well.

<relationship> element

The <relationship> element contains no character data.

NameRequiredTypeDefault valueDetails
typerequiredstringNoneMUST be one of: "contained-within","adjacent-to", or "contains"

<label> element

Todo. At the f2f we agreed it would be label instead of name, and that multiples can exist, and one per language can be marked as primary

id representation

At F2F2 we discussed using URI fragments as IDs, as in XML. Using XML Base we could build a full URI that could then be used to identify the entire POI.

<category> element

The <category> element is a child of the <poi> element. It is used to identify a category scheme and a category within that scheme, as well as one or more labels for the category.

The <category> element MUST contain one or more <label> elements, and zero or more <association> elements.

See ISSUE-24.
I adjusted the Atom category element, to support multiple human readable labels via label sub elements and I try to give some meaning to the term attribute when there is no scheme.

NameRequiredTypeDefault valueDetails
schemeoptionalURINoneURI that identifies the categorization scheme, does not need to be dereferencable
termrequiredstringNoneThe name of the category, in the context of the scheme, or when scheme is missing, it is relevant only as an opaque string to identify the category.


TBD. See ISSUE-18.

<time> element

We discussed at F2F2 basing this on other standards' time representations.
This section now represents times as defined in XML Schema Datatypes.
This is ISSUE-26.

NameRequiredTypeDefault valueDetails
schemeoptionalURINoneURI that identifies the categorization scheme, does not need to be dereferencable
termrequiredstringNoneThe name of the category, in the context of the scheme, or when scheme is missing, it is relevant only as an opaque string to identify the category.

XML Example

This example was just something I generated while thinking through the XML syntax, it hasn't been updated to be in sync with what is in the document, so it may differ.

XML Schema

This is a very rough RELAX NG schema for the XML syntax. It is not guaranteed to work or be in sync with the rest of the document for now.

Use Cases