Independent Rail Replacement Location (RRL) XML Schema. This schema carries data that is not included in NaPTAN but, where practical, mirrors the NaPTAN 2.4 XML structure. Equivalent concepts generally use the same element names, ordering and underlying data types to maximise consistency for consumers familiar with NaPTAN. While this XSD uses structures and validation rules derived from NaPTAN where appropriate, it contains a number of RRL-specific elements and business rules that do not exist within the NaPTAN 2.4 schema. Consumers should therefore treat this as a distinct schema and should not assume full compatibility with NaPTAN. The RRL dataset remains a distinct schema and includes a small number of deliberate deviations required to support rail replacement location data and pilot-specific business rules. StopClassification/RailReplacement is the principal extension. These elements have no direct NaPTAN equivalent. CrsRef shares the NaPTAN CrsCodeType rule but is used here for a different purpose and therefore appears in a different location within the model. Language is carried on a local, unqualified lang attribute rather than the xml:lang attribute NaPTAN uses. This keeps the schema a single self-contained file with no external import, and makes the XML and JSON forms of RRL consistent with each other. It is a deliberate deviation from NaPTAN: consumers expecting xml:lang must read lang instead. English (en) and Welsh (cy) are supported for the pilot, but the schema deliberately permits additional valid language codes without requiring a schema change. Each section below identifies the NaPTAN 2.4 module or concept from which the definition was derived. Schema for exchanging Rail Replacement Location data. @CreationDateTime, @ModificationDateTime, @Modification, @RevisionNumber, @FileName, @Version Definitions of rail replacement stop points. Mandatory in RRL; the equivalent NaPTAN element is optional. The version of the schema that the RRL instance document was written against. Stop point keys must be unique within the document. Nature of last modification. A restriction of the NaPTAN enumeration, which also allows delta and archive. An integer that should be increased by one each time the unit it refers to is modified. Grouping for document change metadata. Base for a versioned object carrying its own timestamps. Modification and RevisionNumber are required in RRL; both are optional in NaPTAN. Language of a natural language value. NaPTAN uses the standard xml:lang attribute from the XML namespace. RRL uses a local, unqualified lang attribute instead, so that this schema is a single self-contained file with no external import. This is a deliberate deviation from NaPTAN. It also makes the XML and JSON forms of RRL identical in this respect, since JSON has no namespaces and already carries a plain lang key. English (en) and Welsh (cy) are in use for the pilot. The type deliberately permits any well-formed language tag so that further languages need no schema change. The pattern matches the JSON schema's LanguageCode exactly: a two or three letter primary subtag with optional further subtags. A string that requires at least one character of text, of which at least one must be non-whitespace. NaPTAN checks only the length; requiring a visible character as well is a restriction of the NaPTAN rule, so RRL values remain NaPTAN-valid. A name that requires at least one character of text and forbids certain reserved characters. @lang. ISO language code (default is en). A natural language name that requires at least one character of text and forbids certain reserved characters. @lang. ISO language code (default is en). A string containing a phrase in a natural language. As NaturalLanguagePlaceNameStructure, but lang is required. Used only within AlternativeDescriptors, where the language of the alternative is the point of the entry. This is a restriction of the NaPTAN rule, not a departure from it. As NaturalLanguageStringStructure, but lang is required. A restriction of the NaPTAN enumeration, which also allows IrishOS. Grid and WGS84 coordinates for the same point. Position of a point. NaPTAN allows a choice of grid only, WGS84 only, or a Translation carrying both; RRL requires the Translation branch, so every location carries both systems. An RRL Location is therefore valid against the NaPTAN LocationStructure. NPTG coding for a locality identifier. ab999999, where a is E or N, b is 0 or S, 9 is numeric. Nationally unique identifier for a stop point. Mirrors the NaPTAN 2.4 rule: administrative area code, separator, then a locally assigned identifier. ATCO code for a rail replacement location, in the form 911 + 0 + CRS code + sequence number, for example 9110OCK0, 9110OCK1, 9110AMR0. The 911 area code is reserved for rail replacement data. The sequence number starts at zero for the first location associated with a CRS code and increments for each further location at the same station. Derived by restriction from AtcoCodeType, so an RRL ATCO code is also a valid NaPTAN ATCO code. The inherited rule caps the CRS code plus sequence number at eight characters, which allows sequence numbers up to five digits. MarkedStopAtcoCode is deliberately NOT this type: it references an existing NaPTAN stop in its own administrative area, and so uses the general AtcoCodeType. Classification of the stop. RRL is not a NaPTAN 2.4 stop type; it is introduced by this schema. Rail replacement location. A rail replacement stop point. @CreationDateTime, @ModificationDateTime, @Modification, @RevisionNumber Primary descriptor for the stop. NaPTAN also allows ShortCommonName, Landmark, Crossing and Indicator here; RRL omits them. Free text description of the stop. No NaPTAN equivalent; the nearest NaPTAN concept is StopPoint/Notes. As DescriptorGroup, but every value must carry lang. Descriptors for the stop in other languages. Neither this element nor the primary Descriptor carries change metadata of its own: both are versioned by the parent StopPoint. A change to either language therefore updates the same StopPoint ModificationDateTime and RevisionNumber, so no change goes untracked, but a revision cannot be attributed to one language rather than the other. NaPTAN places creation and revision details on each alternative descriptor entry, treating them as an independently maintained list. If that granularity is wanted later, apply an attributeGroup carrying a required CreationDateTime and optional ModificationDateTime, Modification and RevisionNumber to the Descriptor element below. Where the stop is. NaPTAN also allows LocalityName, AlternativeNptgLocalities, MainNptgLocalities, Suburb, Town and LocalityCentre here; RRL omits them. Location is optional here, which is a deliberate deviation: NaPTAN requires it. In the published RRL dataset a minority of records carry a locality but no surveyed coordinates, and those are almost all rail replacement only stops. Making Location optional keeps the locality reference on such records rather than dropping the whole Place. If the source data is completed so that every record has coordinates, this should be tightened back to mandatory to match NaPTAN. Three character CRS code identifying a station. Mirrors the NaPTAN 2.4 CrsCodeType rule exactly. NaPTAN carries a CrsRef of its own under StopClassification/OffStreet/Rail/AnnotatedRailRef for a different purpose; the RRL CrsRef deliberately keeps its own position here, but shares the NaPTAN rule. Station Facility Owner code, identifying the Train Operating Company responsible for the station. Exactly two characters, as in the published dataset. Rail replacement details. This section is the intended deviation from NaPTAN; it replaces the OnStreet/OffStreet choice that NaPTAN carries at this position. Named to match the SFOCode column of the published RRL CSV, which is already in circulation. NaPTAN naming convention would suggest SfoRef, but alignment with the published dataset takes precedence here. The NaPTAN stop this rail replacement location is marked against. Typed as AtcoCodeType, since it references a NaPTAN stop point.