Validation Rules

This chapter enumerates all validation rules supported by xbridge. Each rule has a unique identifier, a severity level, a human-readable description, and attributes controlling when the rule is executed.

Rules are organized into three categories based on the input format:

• XML Instance Rules — apply when validating .xbrl / .xml files (or XML-in-ZIP).

• CSV Report Package Rules — apply when validating .zip files containing xBRL-CSV.

• Submission Package Naming Rules — apply to file names for both XML and CSV.

Tip

Implementation status and message templates for each rule can be found in the rule registry at src/xbridge/validation/registry.json.

Rule Attributes

Attribute	Values	Meaning
EBA	Yes / No	When Yes, the rule only runs if the eba parameter is True.
EBA ref	Section	Cross-reference to the EBA Filing Rules v5.8 section that this rule implements.
Post-conv.	Yes / No	(CSV only) When No, the rule is skipped if post_conversion is True.

Rules with EBA = No are standard XBRL 2.1 or xBRL-CSV 1.0 structural checks. Rules with EBA = Yes are requirements imposed by the EBA Filing Rules (v5.8) that go beyond the base XBRL/xBRL-CSV specifications.

Input Format Detection

The validation engine accepts .xbrl, .xml, and .zip files. For .zip files, the engine inspects the archive contents to determine the rule set:

• If the ZIP contains reports/report.json (at any nesting level), it is treated as an xBRL-CSV report package and CSV rules apply.

• If the ZIP contains exactly one .xbrl/.xml file at the root level (and no reports/report.json), it is treated as an XML-in-ZIP and XML rules apply. The inner file is extracted for validation.

• If the ZIP contains multiple .xbrl/.xml files at root level, or no recognized content, validation raises an error.

1. XML Instance Rules

Structural and compliance checks on xBRL-XML instances.

1.1 XML Well-formedness and Encoding

Rule ID	Severity	EBA	EBA ref	Description
XML-001	ERROR	No	–	The file MUST be well-formed XML.
XML-002	ERROR	Yes	1.4	The file MUST use UTF-8 encoding. (encodingNotUtf8)

1.2 Root Element

Rule ID	Severity	EBA	EBA ref	Description
XML-003	ERROR	No	–	The root element MUST be xbrli:xbrl.

1.3 Schema Reference (schemaRef)

Rule ID	Severity	EBA	EBA ref	Description
XML-010	ERROR	Yes	1.5	Exactly one link:schemaRef element MUST be present. (multipleSchemaRefs)
XML-012	ERROR	Yes	1.5	The schemaRef MUST resolve to a known entry point URL. (inappropriateSchemaRef)

1.4 Filing Indicators

Rule ID	Severity	EBA	EBA ref	Description
XML-020	ERROR	Yes	1.6	At least one find:fIndicators element MUST be present.
XML-021	ERROR	Yes	1.6	At least one filing indicator (positive or negative) MUST exist. (missingFilingIndicators)
XML-024	ERROR	Yes	1.6	Filing indicator values MUST match the label resources in the taxonomy. (invalidFilingIndicatorValue)
XML-025	ERROR	Yes	1.6	No duplicate filing indicators for the same reporting unit. (duplicateFilingIndicator)
XML-026	ERROR	Yes	1.6	The context referenced by filing indicators MUST NOT contain xbrli:segment or xbrli:scenario. (invalidContextForFilingIndicator)

1.5 Context Structure

Rule ID	Severity	EBA	EBA ref	Description
XML-030	ERROR	Yes	2.10	All xbrli:period date elements MUST be xs:date (no dateTime, no timezone). (periodWithTimeContent, periodWithTimezone)
XML-031	ERROR	Yes	2.13	All periods MUST be instants (not durations). (nonInstantPeriodUsed)
XML-032	ERROR	Yes	2.13	All periods MUST refer to the same reference date. (multiplePeriodsUsed)
XML-033	ERROR	Yes	2.9	All xbrli:identifier content and @scheme MUST be identical across contexts. (multipleIdentifiers)
XML-034	ERROR	Yes	2.14	xbrli:segment elements MUST NOT be used. (segmentUsed)
XML-035	ERROR	Yes	2.15	xbrli:scenario children MUST only be xbrldi:explicitMember and/or xbrldi:typedMember. (scenarioContainsNonDimensionContent)

1.6 Fact Structure

Rule ID	Severity	EBA	EBA ref	Description
XML-040	ERROR	Yes	2.17	The @decimals attribute MUST be used (not @precision). (precisionUsed)
XML-041	ERROR	No	–	The @decimals value MUST be a valid integer, “INF”, or absent for non-numeric.
XML-042	ERROR	Yes	2.19	@xsi:nil MUST NOT be used on facts. (nilUsed)
XML-043	ERROR	Yes	2.19	String-type facts MUST NOT be empty. (emptyUsed)

1.7 Unit Structure

Rule ID	Severity	EBA	EBA ref	Description
XML-050	ERROR	Yes	2.23	xbrli:unit children MUST refer to the XBRL International Unit Type Registry (UTR). (nonUtrUnit)

1.8 Document-level Checks

Rule ID	Severity	EBA	EBA ref	Description
XML-060	ERROR	Yes	2.1	@xml:base MUST NOT appear anywhere in the document. (xmlBaseUsed)
XML-061	ERROR	Yes	2.4	link:linkbaseRef MUST NOT be used. (linkbaseRefUsed)
XML-062	ERROR	Yes	2.11	xbrli:forever MUST NOT be used. (foreverUsed)
XML-063	ERROR	Yes	1.14	@xsd:schemaLocation / @xsd:noNamespaceSchemaLocation MUST NOT be used. (schemaLocationAttributeUsed)
XML-064	ERROR	Yes	1.15	xi:include MUST NOT be used. (xIncludeUsed)
XML-065	WARNING	Yes	1.13	The XML standalone declaration SHOULD NOT be used. (standaloneDocumentDeclarationUsed)
XML-066	WARNING	Yes	2.7	Unused contexts SHOULD NOT be present. (unusedContext)
XML-067	WARNING	Yes	2.7	Duplicate contexts SHOULD NOT be present. (duplicateContext)
XML-068	WARNING	Yes	2.22	Unused units SHOULD NOT be present. (unusedUnit)
XML-069	WARNING	Yes	2.21	Duplicate units SHOULD NOT be present. (duplicateUnit)

1.9 Taxonomy Conformance

Rule ID	Severity	EBA	EBA ref	Description
XML-070	ERROR	No	–	All fact element names (concepts) MUST be defined in the taxonomy for the referenced entry point.
XML-071	ERROR	No	–	All explicit dimension QNames used in contexts MUST be defined as dimensions in the taxonomy.
XML-072	ERROR	No	–	All dimension member values MUST be valid members for their respective dimension as defined in the taxonomy.

1.10 Entity Identification

Rule ID	Severity	EBA	EBA ref	Description
EBA-ENTITY-001	ERROR	Yes	2.8	The entity identifier @scheme MUST be one of the accepted schemes (http://standards.iso.org/iso/17442 for LEI, https://eurofiling.info/eu/rs for qualified identifiers). (inappropriateScheme)
EBA-ENTITY-002	ERROR	Yes	2.8	The entity identifier value MUST follow the reporting subject conventions (LEI format, consolidation suffix, etc.). (unacceptableIdentifier)

1.11 Decimals Accuracy

Rule ID	Severity	EBA	EBA ref	Description
EBA-DEC-001	ERROR	Yes	2.18	Monetary facts: @decimals MUST be >= -4 (from 01/04/2025; >= -6 for FP, ESG, Pillar3, REM_DBM modules).
EBA-DEC-002	ERROR	Yes	2.18	Percentage facts: @decimals MUST be >= 4.
EBA-DEC-003	ERROR	Yes	2.18	Integer facts: @decimals MUST be 0.
EBA-DEC-004	WARNING	Yes	2.18	Decimals SHOULD be a realistic indication of accuracy (not excessively high).

1.12 Currency Rules

Rule ID	Severity	EBA	EBA ref	Description
EBA-CUR-001	ERROR	Yes	3.1	All monetary facts without CCA dimension eba_CA:x1 (or qAEA eba_qCA:qx2000) MUST use a single “reporting currency”. (multipleReportingCurrencies)
EBA-CUR-002	ERROR	Yes	3.1	Facts with CCA eba_CA:x1 (or qAEA eba_qCA:qx2000) MUST be expressed in their currency of denomination. (currencyOfDenomination)
EBA-CUR-003	ERROR	Yes	3.1	For facts with CUS or CUA dimension, the unit currency MUST be consistent with the dimension value. (inconsistentCurrencyUnitAndDimension)

1.13 Non-monetary Numeric Values

Rule ID	Severity	EBA	EBA ref	Description
EBA-UNIT-001	ERROR	Yes	3.2	Non-monetary numeric values MUST use the “pure” unit. (pureUnitNotUsedForMonetaryValue)
EBA-UNIT-002	WARNING	Yes	3.2	Rates, percentages and ratios SHOULD use decimal notation (e.g. 0.0931 not 9.31). A warning is raised when the absolute value exceeds 50. (useDecimalFractions)

1.14 Additional Checks

Rule ID	Severity	EBA	EBA ref	Description
EBA-2.5	WARNING	Yes	2.5	XML comments are ignored; data SHOULD only appear in contexts, units, and facts. (xmlCommentPresent)
EBA-2.16.1	ERROR	Yes	2.16	No multi-unit fact sets; facts MUST NOT differ only by unit. (factsDifferingOnlyByUnit)
EBA-2.24	ERROR	Yes	2.24	Monetary units MUST be basic ISO 4217 without scaling. (nonBasicMonetaryUnit)
EBA-2.25	WARNING	Yes	2.25	Footnotes are ignored. link:footnoteLink SHOULD NOT be present. (footnotePresent)

1.15 Guidance

Rule ID	Severity	EBA	EBA ref	Description
EBA-GUIDE-001	WARNING	Yes	3.4	Unused namespace prefixes SHOULD NOT be declared. (unusedNamespacePrefix)
EBA-GUIDE-002	WARNING	Yes	3.4	Namespace prefixes SHOULD mirror canonical prefixes. (notRecommendedNamespacePrefix)
EBA-GUIDE-003	WARNING	Yes	3.4	Unused @id on facts SHOULD NOT be present. (unusedFactId)
EBA-GUIDE-004	WARNING	Yes	3.4	String values SHOULD be as short as possible. (excessiveStringLength)
EBA-GUIDE-005	WARNING	Yes	3.4	Namespace declarations SHOULD be on the document element only. (unexpectedNamespaceDeclarations)
EBA-GUIDE-006	WARNING	Yes	3.4	Avoid multiple prefix declarations for the same namespace. (multiplePrefixForNamespace)
EBA-GUIDE-007	WARNING	Yes	3.4	String facts and domain values SHOULD NOT start/end with whitespace. (leadingOrTrailingSpacesInText)

2. CSV Report Package Rules

Structural and compliance checks on xBRL-CSV report packages per the xBRL-CSV 1.0 specification (REC 2021-10-13, errata 2023-04-19).

2.1 Report Package Structure

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
CSV-001	ERROR	No	–	No	The report package MUST be a valid ZIP archive.
CSV-002	ERROR	No	–	No	The ZIP MUST contain META-INF/reportPackage.json.
CSV-003	ERROR	No	–	No	reportPackage.json documentType MUST be "https://xbrl.org/report-package/2023".
CSV-004	ERROR	No	–	No	The ZIP MUST contain exactly one reports/ folder with exactly one report.json file.
CSV-005	ERROR	No	–	No	The ZIP archive MUST NOT contain extraneous files (.DS_Store, Thumbs.db, __MACOSX/, etc.).
CSV-006	ERROR	No	–	No	The ZIP archive MUST contain a single top-level directory (STLD) as required by the XBRL Report Package 1.0 specification.

2.2 Metadata File (report.json)

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
CSV-010	ERROR	No	–	No	report.json MUST be valid JSON.
CSV-011	ERROR	No	–	No	documentInfo.documentType MUST be "https://xbrl.org/2021/xbrl-csv".
CSV-012	ERROR	Yes	1.5	No	documentInfo.extends MUST contain exactly one entry point URL.
CSV-013	ERROR	Yes	1.5	No	The extends URL MUST resolve to a published JSON entry point. (inappropriateTaxonomyRef)
CSV-014	ERROR	No	–	No	JSON representation constraints MUST be met (no duplicate keys, correct types).
CSV-015	ERROR	No	–	No	All namespace prefixes used in dimension values MUST be declared in documentInfo.namespaces.
CSV-016	ERROR	No	–	No	All URI aliases MUST resolve to valid absolute URIs.

2.3 Parameters File (parameters.csv)

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
CSV-020	ERROR	Yes	–	No	parameters.csv MUST exist in the reports/ folder.
CSV-021	ERROR	Yes	–	No	The header row MUST be name,value.
CSV-022	ERROR	Yes	–	No	entityID parameter MUST be present and non-empty.
CSV-023	ERROR	Yes	2.10	No	refPeriod parameter MUST be present, valid xs:date, and without timezone.
CSV-024	ERROR	Yes	–	No	baseCurrency parameter MUST be present if any fact references base currency.
CSV-025	ERROR	Yes	–	No	Decimals parameters MUST be present for each type of metric in the package.
CSV-026	ERROR	Yes	–	No	Decimals values MUST be valid integers or “INF”.

2.4 Filing Indicators File (FilingIndicators.csv)

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
CSV-030	ERROR	Yes	–	No	FilingIndicators.csv MUST exist in the reports/ folder.
CSV-031	ERROR	Yes	–	No	The header row MUST be templateID,reported.
CSV-032	ERROR	Yes	1.6	No	Every templateID MUST be a valid filing indicator code from the taxonomy. (invalidFilingIndicatorValue)
CSV-033	ERROR	Yes	–	No	reported values MUST be boolean (true / false / 1 / 0).
CSV-034	ERROR	Yes	1.6	No	A filing indicator MUST be present for each template in the module. (missingFilingIndicators)
CSV-035	ERROR	Yes	1.6	No	No duplicate templateID entries. (duplicateFilingIndicator)

2.5 Data Table CSV Files

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
CSV-040	ERROR	No	–	No	CSV files MUST use UTF-8 encoding.
CSV-041	ERROR	No	–	No	The first row MUST be the header row. No header cell may be empty.
CSV-042	ERROR	Yes	–	No	All columns defined in the corresponding JSON metadata MUST be present in the CSV header.
CSV-043	ERROR	No	–	No	Each row MUST contain the same number of fields as the header.
CSV-044	ERROR	Yes	–	No	Key columns MUST contain a value for each reported fact.
CSV-045	ERROR	Yes	–	No	Special values (#empty, #none, #nil, any value starting with #) MUST NOT be used in fact or key columns.
CSV-046	ERROR	Yes	–	No	The “Decimals Suffix” feature MUST NOT be used; decimals MUST come from parameters.csv.
CSV-047	ERROR	No	–	No	Strings containing commas, linefeeds, or double quotes MUST be enclosed in double quotes, with internal double quotes escaped by doubling.
CSV-049	ERROR	Yes	–	No	Data tables for non-reported templates (filing indicator = false) MUST NOT exist.

2.6 Fact-level Validation

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
CSV-050	ERROR	Yes	2.19	No	A fact MUST NOT be reported as #nil. (nilUsed)
CSV-051	ERROR	Yes	2.19	No	A fact MUST NOT be reported as #empty. (emptyUsed)
CSV-052	ERROR	Yes	2.16	No	Duplicate business facts (same concept, same dimensions) across tables are allowed only as complete duplicates. (duplicateFactXBRL-CSV)

2.7 Taxonomy Conformance

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
CSV-060	ERROR	No	–	No	All metric references in data tables MUST be defined in the taxonomy for the referenced entry point.
CSV-061	ERROR	No	–	No	All dimension columns MUST correspond to dimensions defined in the taxonomy.
CSV-062	ERROR	No	–	No	All dimension member values MUST be valid members for their respective dimension as defined in the taxonomy.

2.8 Entity Identification

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
EBA-ENTITY-001	ERROR	Yes	2.8	No	The entityID parameter scheme MUST be one of the accepted schemes. (inappropriateScheme)
EBA-ENTITY-002	ERROR	Yes	2.8	No	The entityID parameter value MUST follow the reporting subject conventions. (unacceptableIdentifier)

2.9 Decimals Accuracy

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
EBA-DEC-001	ERROR	Yes	2.18	No	Monetary facts: decimals MUST be >= -4 (from 01/04/2025; >= -6 for FP, ESG, Pillar3, REM_DBM modules).
EBA-DEC-002	ERROR	Yes	2.18	No	Percentage facts: decimals MUST be >= 4.
EBA-DEC-003	ERROR	Yes	2.18	No	Integer facts: decimals MUST be 0.
EBA-DEC-004	WARNING	Yes	2.18	No	Decimals SHOULD be a realistic indication of accuracy (not excessively high).

2.10 Currency Rules

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
EBA-CUR-001	ERROR	Yes	3.1	No	All monetary facts without CCA dimension MUST use a single “reporting currency”. (multipleReportingCurrencies)
EBA-CUR-002	ERROR	Yes	3.1	No	Facts with CCA dimension MUST be expressed in their currency of denomination. (currencyOfDenomination)
EBA-CUR-003	ERROR	Yes	3.1	No	For facts with CUS or CUA dimension, the currency MUST be consistent with the dimension value. (inconsistentCurrencyUnitAndDimension)

2.11 Non-monetary Numeric Values

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
EBA-UNIT-001	ERROR	Yes	3.2	Yes	Non-monetary numeric values MUST use the “pure” unit. (pureUnitNotUsedForMonetaryValue)
EBA-UNIT-002	WARNING	Yes	3.2	Yes	Rates, percentages and ratios SHOULD use decimal notation. (useDecimalFractions)

2.12 Decimal Representation

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
EBA-REP-001	ERROR	Yes	3.3	Yes	Numeric facts MUST be expressed in specified units without scaling. Values MUST NOT be truncated to fit the decimals setting.

2.13 Additional Checks

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
EBA-2.16.1	ERROR	Yes	2.16	Yes	No multi-unit fact sets. (factsDifferingOnlyByUnit)
EBA-2.24	ERROR	Yes	2.24	Yes	Monetary units MUST be basic ISO 4217, no scaling.

2.14 Guidance

Rule ID	Severity	EBA	EBA ref	Post-conv.	Description
EBA-GUIDE-002	WARNING	Yes	3.4	Yes	Namespace prefixes SHOULD mirror canonical prefixes. (notRecommendedNamespacePrefix)
EBA-GUIDE-004	WARNING	Yes	3.4	Yes	String values SHOULD be as short as possible. (excessiveStringLength)
EBA-GUIDE-007	WARNING	Yes	3.4	Yes	String facts and domain values SHOULD NOT start/end with whitespace. (leadingOrTrailingSpacesInText)

3. Submission Package Naming Rules

File naming conventions for EBA report submissions. These rules validate the file name structure for both bare .xbrl/.xml files and .zip archives. They apply to both xBRL-XML and xBRL-CSV submissions when the eba parameter is enabled.

The EBA requires submission files to follow a specific naming structure:

ReportSubject_Country_FrameworkCodeModuleVersion_Module_ReferenceDate_CreationTimestamp

See EBA Filing Rules v5.8, “File naming structure for remittance to the EBA” (pp. 57–61).

Naming rules EBA-NAME-001 through EBA-NAME-060 validate the file stem and apply regardless of whether the input is a bare .xbrl file or a .zip archive. EBA-NAME-070 and EBA-NAME-071 validate the relationship between the ZIP archive name and its inner content, and are skipped for bare files.

3.1 Overall File Name Structure

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-001	ERROR	Yes	File naming	The file name MUST follow the pattern ReportSubject_Country_FrameworkCodeModuleVersion_Module_ReferenceDate_CreationTimestamp (exactly six underscore-separated components plus extension).

3.2 Report Subject

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-010	ERROR	Yes	File naming	For modules with _con/_ind in the name (or before reference date 31/12/2022): the ReportSubject MUST be the LEI (individual/consolidated) or LEI + .CRDLIQSUBGRP (liquidity subgroup).
EBA-NAME-011	ERROR	Yes	File naming	For modules without _con/_ind (from reference date 31/12/2022): individual reports MUST use LEI + .IND, consolidated MUST use LEI + .CON, liquidity subgroup MUST use LEI + .CRDLIQSUBGRP.
EBA-NAME-012	ERROR	Yes	File naming	For country-level aggregate reports: the ReportSubject MUST be the ISO country code (two capital letters) + 000 + the aggregation type suffix.
EBA-NAME-013	ERROR	Yes	File naming	For authority-level aggregate reports: the ReportSubject MUST be the authority code + .AUTALL.
EBA-NAME-014	ERROR	Yes	File naming	For MICA reports: the ReportSubject MUST be IssuerID-TokenID + .IND.

3.3 Country

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-020	ERROR	Yes	File naming	The Country component MUST be a valid ISO 3166-1 alpha-2 country code in uppercase.

3.4 Framework Code and Module Version

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-030	ERROR	Yes	File naming	The FrameworkCodeModuleVersion MUST be the DPM/XBRL framework code in uppercase followed by the module version as a 6-digit number XXYYZZ.

3.5 Module

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-040	ERROR	Yes	File naming	The Module component MUST be the taxonomy module name in uppercase without underscores.

3.6 Reference Date

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-050	ERROR	Yes	File naming	The ReferenceDate component MUST be in YYYY-MM-DD format.

3.7 Creation Timestamp

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-060	ERROR	Yes	File naming	The CreationTimestamp component MUST be in YYYYMMDDhhmmssfff format.

3.8 Inner Content Naming

Rule ID	Severity	EBA	EBA ref	Description
EBA-NAME-070	ERROR	Yes	File naming	(XML) The ZIP MUST contain exactly one .xbrl file whose base name matches the ZIP file name.
EBA-NAME-071	ERROR	Yes	File naming	(CSV) The root folder inside the ZIP MUST be named identically to the ZIP file (without the .zip extension).

Rule Coverage Summary

Category	Count	Rules
XML-only format rules	34	XML-001 – XML-072
XML-only EBA rules	7	EBA-2.5, EBA-2.25, EBA-GUIDE-001, -003, -005, -006
CSV-only format rules	40	CSV-001 – CSV-062
Shared EBA rules	17	EBA-ENTITY, EBA-DEC, EBA-CUR, EBA-UNIT, EBA-REP, EBA-2.16.1, EBA-2.24, EBA-GUIDE-002/-004/-007
Submission naming rules	14	EBA-NAME-001 – EBA-NAME-071
Total unique rules	98 + 14 naming

Effective rules per format:

Format	Count	Composition
XML	58	34 XML-only + 7 XML-only EBA + 17 shared EBA
CSV	57	40 CSV-only + 17 shared EBA
Naming	14	Applied to both formats when eba=True