FORMATS / IDENTIFIERS / METHODS
Documentary reference library
Find an identifier, unit, HTTP status or data convention, then open the method explaining its use and limits.
193 references · page 1 of 9
| Object to check | Code or notation | Context and use |
|---|---|---|
| Link a legal unit to its establishments | SIREN · NIC · SIRET | Before matching French records, choose the required level. An establishment record and its legal-unit record can both be correct while showing different addresses or activities. |
| Person, organisation and publication: three identities | ORCID · ROR · DOI | A bibliographic record links several objects. Check each relationship in the consulted material rather than transferring an identifier’s credibility to the entire result. |
| Read GeoJSON coordinate order | coordinates[0] · coordinates[1] · WGS 84 / CRS84 | Inspect the actual input format before copying coordinates. Do not automatically swap a pair because another tool displays its fields in a different order. |
| Distinguish a dataset, distribution and service | dcat:Dataset · dcat:Distribution · dcat:DataService | When two links appear to describe the same data, compare their objects before counting two sources. Organise collection so each value can be traced to the representation actually consulted. |
| Read an archive at record level | WARC-Target-URI · WARC-Date · WARC-Type | A page replay helps reading; archive metadata identifies the examined resource. Retain both levels when a conclusion depends on an earlier state. |
| Parse an ECLI before citing a decision | ECLI · country / court · year / ordinal | The official identifier ECLI:EU:C:1998:27 provides a real structural example. Retrieve the decision and its text rather than inferring its meaning from the identifier. |
| Count patent publications or families | DOCDB · INPADOC · publication ≠ family | Before counting, state what constitutes a row and which rule groups documents. A comparison loses meaning when it silently mixes publications and families. |
| What robots.txt actually describes | User-agent · Allow · Disallow | Separate a published rule from the response actually received by a crawler. For an important path, retain the consulted file and the URL check. |
| A real satellite image with two dates to retain | Landsat 9 · NASA SVS · 31172 · NASA / USGS | This observation distinguishes acquisition from publication of its record. Treat the image as an identified document, then consider the metadata needed before taking measurements. |
| Google: distinguish crawlers and results | Googlebot · Googlebot-Image · Googlebot-Video | A crawl record should identify the resource and agent. Use documented names to read logs, then inspect results in the search surface being studied. |
| Bing: separate three crawler roles | bingbot · AdIdxBot · MicrosoftPreview | Identify a request’s function before interpreting server logs. A preview request and a search crawl answer different questions. |
| DuckDuckGo: separate search and assisted answers | DuckDuckBot · DuckAssistBot | When studying a citation, record the feature observed rather than treating all requests as one activity. The two documented crawlers serve different uses. |
| Brave: a distinctive crawling control | User-Agent · Googlebot · noindex | The crawler documentation describes behaviour relevant to interpreting requests. Do not look only for a string containing the service name before deciding it is absent from your logs. |
| LEI: legal identity and group relationship | LEI · Level 1 · Level 2 · NO_LEI | GLEIF separates identity data from accounting consolidation relationships. Establishing a group relationship therefore requires more than reading the entity’s name. |
| EDGAR: find older filings | CIK##########.json · filings.recent · filings.files | The SEC assigns CIKs to filing entities and individuals. The public reading API pads this number to ten digits with leading zeros. Its main response is not necessarily the complete history. |
| Clinical study: five fields with different dates | nctId · studyFirstPostDateStruct · primaryCompletionDateStruct · resultsFirstPostDateStruct · lastUpdatePostDateStruct | These ClinicalTrials.gov API fields belong to identificationModule and statusModule inside protocolSection. They distinguish identification, study conduct and publication; not all describe a medical event. |
| M49: a hierarchy without double counting | 001 · 150 · 155 · 250 · 004 | M49 assigns three-digit numeric codes to countries or areas and geographic groupings. ISO letter codes appear alongside them but belong to another system. These are actual mappings from the consulted official table. |
| RDAP: attach each date to the right object | events[].eventAction · events[].eventAction · events[].eventAction · entities[].roles | RFC 9083 separates an event’s action, date and optional actor. Identify its object—domain, entity or another resource—before placing a date on a timeline. Events may be nested in different objects. |
| Europe/Paris: two instants, the same displayed time | 2025-10-26T00:30:00Z · 2025-10-26T01:30:00Z · 2025-03-30T00:30:00Z · 2025-03-30T01:30:00Z | On 26 October 2025, two UTC instants one hour apart both map to 02:30 in Europe/Paris with different offsets. This table applies IANA tzdb 2025b rules to four real instants; it is not a fictional case. |
| Companies House: period, deadline and filing are different | company_number · accounts.last_accounts.period_end_on · accounts.next_accounts.due_on · links.filing_history · links.persons_with_significant_control | The company profile and filing history are separate resources. The public companyProfile specification also separates the period covered by accounts from the next filing deadline. Do not merge them into one “accounts date”. |
| CPV: choose the procurement search level | XX000000-Y · XXX00000-Y · XXXX0000-Y · XXXXX000-Y · XXXXXXXX-Y | The Common Procurement Vocabulary describes what is being bought. Its main vocabulary is hierarchical; the supplementary vocabulary adds qualitative detail. X marks a position below, not an assigned code. |
| Find a Tender: intention to contract or contract entered into? | UK6 · UK7 · UK12 | For Procurement Act 2023 notices, “contract award notice” has a different function from the older notice with the same name. Cabinet Office guidance separates the announcement before entering into the contract from the later publication of its details. |
| USAspending: choose the key before summing | contract_award_unique_key · assistance_award_unique_key · federal_action_obligation · total_obligated_amount · sub-award | The Federal Spending Guide separates prime awards, their transactions and sub-awards. A transaction may create or modify an award. A summary rolls up related transactions; these rows are not independent amounts to add together. |
| FTS: define the scope of an EU funding search | FTS · EC direct · FTS · EDF · Year · Shared management | The Commission’s official page gives two historical FTS starting points and explains that the year is when an amount was booked in the accounts. Preserve management scope, period and expenditure type. |
From format to fact: three separate checks
Recognise the format
An identifier matching a pattern or checksum can still refer to the wrong entity. A format check catches typing errors; it does not verify the holder.
Find the right object
Open the corresponding register or document. Compare its name, scope, version and period with your question. Retain technical identifiers without translating them.
Qualify the conclusion
Separate what the source declares, what you observed and what remains unestablished. A value without a unit, period or definition cannot support a reliable comparison.
Notation examples explain a rule. They are neither certification nor a live check of your dossier.
Check documentary identifiers