Docs for schema item url in Open Travel (OTA)

Uri of the creating system. The URI should be an URL and be globally unique. Should only be omitted when the context is clearly implied for the containing document. Identifier provides the ability to create a globally unique identifier. For the identifier to be globally unique it must have a system provided identifier and the system must be identified using a global naming authority. System identification uses the domain naming system (DNS) to assure they are globally unique and should be an URL. The system provided ID will typically be a primary or surrogate key in a database.

<xsd:attribute name="url" type="xsd:anyURI" use="optional"> <xsd:annotation> <xsd:documentation source="Description">Uri of the creating system. The URI should be an URL and be globally unique. Should only be omitted when the context is clearly implied for the containing document.</xsd:documentation> <xsd:documentation source="Implementer">Identifier provides the ability to create a globally unique identifier. For the identifier to be globally unique it must have a system provided identifier and the system must be identified using a global naming authority. System identification uses the domain naming system (DNS) to assure they are globally unique and should be an URL. The system provided ID will typically be a primary or surrogate key in a database.</xsd:documentation> </xsd:annotation> </xsd:attribute>

Definition Type:	Attribute
Name:	url
Namespace:	http://www.opentravel.org/OTM/Common/v4
Type:	anyURI:http://www.w3.org/2001/XMLSchema
Containing Schema:	Common_4_0_0.xsd
Use	Optional
Documentation:	Uri of the creating system. The URI should be an URL and be globally unique. Should only be omitted when the context is clearly implied for the containing document. Identifier provides the ability to create a globally unique identifier. For the identifier to be globally unique it must have a system provided identifier and the system must be identified using a global naming authority. System identification uses the domain naming system (DNS) to assure they are globally unique and should be an URL. The system provided ID will typically be a primary or surrogate key in a database.