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 4 of 9
| Object to check | Code or notation | Context and use |
|---|---|---|
| Real CPI data: rebase without inventing living-standard comparisons | FP.CPI.TOTL · 2020 → 2023 · FRA · GBR · USA · Δ% | Twelve World Bank observations cover France, the UK and the USA in 2020–2023. The API reports an 8 October 2026 update; consulted 22 October. Changes below are our calculations, rounded to two decimals, not additional World Bank-published rates. |
| Employment, unemployment and inactivity: classify before counting | E · U · O · LF · 1 h · Unit | Labour statistics classify people over a defined period. They do not directly measure contracts, adequate income or job quality. ILO definitions and survey metadata specify classification; administrative registration is a separate system. In the diagram P is the population in scope. |
| Six labour ratios: changing the denominator changes the question | Unemployment · Employment · Activity · Unemployment ratio · Long-term rate · Long-term share | E denotes employed people, U unemployed people, LF = E + U the labour force, P the population in the same scope, and U12 unemployment lasting at least twelve months. Match age, territory, period and definition before comparing. |
| Labour underutilization: read LU1 through LU4 | LU1 · LU2 · LU3 · LU4 · T · F | The ILO’s 2019 guide explains four complementary measures. U is unemployment, LF the labour force, T time-related underemployment and F the potential labour force. T is already in employment; F is outside the labour force. |
| NEET: check age, education and subsampling | NEET · Window · Age · Denominator · Non-response · Sampling | The acronym alone does not define a population. Metadata for the 2024 EU-LFS youth module, certified 5 December 2025, specify scope and differences from regular series. This describes that module, not a universal 15–34 youth definition. |
| France Travail: seven administrative categories, not unemployment rates | A · B · C · D · E · F · G | Insee’s definition updated 7 April 2026 describes A–G. Historical A–E alone no longer describe the current classification: F and G were created in January 2025. These classify registered people, not the entire labour-force survey population. |
| Eurostat slack: four components and an extended labour force | UNE · UEMP_PT · SEEK_NAVL · NSEEK_AVL · SLACK · PC_ELF · d | This historical extract fixes 2024, both sexes and two age bands for the EU, Spain, France and Finland. The 40 lfsi_sla_a observations were updated 10 September 2026 and retrieved 22 October 2026. They are annual data, not the latest available quarter. Published values and flags are retained. |
| ISBN: distinguish edition identity from checksum validity | ISBN-13 · Prefix · Elements · Weights · Check digit · Example · Scope | An ISBN identifies a publishing product: a particular title, edition and format, not every manifestation of a work. The local check follows International ISBN Agency arithmetic to detect transcription errors. It does not query allocation records or identify a book. |
| ISSN and ISSN-L: distinguish medium, serial and article | ISSN · Example · Example X · Medium · ISSN-L · Unit | An ISSN identifies a continuing resource, not every article or issue. ISSN centres and national libraries distinguish medium versions. Before joining catalogues record the actual identifier type and catalogue links. |
| Wikidata: retain statements, qualifiers and references | wd: · p: · ps: · pq: · prov:wasDerivedFrom · pr: · wds: | A direct entity-to-value link does not carry all statement context. Wikibase RDF separates subject, statement node, qualifiers and references. This matters for dated roles, measurement methods and multiple values. Prefixes express graph roles, not trust levels. |
| Wikidata: truthy selects a rank, not certified truth | PreferredRank · NormalRank · DeprecatedRank · wdt: · wikibase:BestRank · Scope | Truthy is a technical projection. For one entity-property pair, preferred statements exclude normal ones from that projection; otherwise normal statements are selected. This is neither automatic source voting nor latest-date selection. |
| Europeana EDM: distinguish object, digital resource and rights | edm:ProvidedCHO · edm:WebResource · ore:Aggregation · edm:isShownAt · edm:isShownBy · edm:hasView · edm:rights · edm:dataProvider | Europeana separates the described cultural heritage object from its web representations. This prevents treating a catalogue page as an image file or one representation’s rights as universal. Class and property names follow EDM documentation checked 22 October 2026. |
| ORCID: inspect assertion origin and public-record limits | Source · Assertion origin · Affiliation · PUBLIC · LIMITED · PRIVATE | ORCID helps distinguish namesakes, but a record combines assertions from different origins. ORCID separates who adds an item from who connects it to the person. Holder-controlled visibility also limits what a public reader can observe. |
| API errors: separate Problem Details messages from HTTP status | Content-Type · type · status · title · detail · instance · Extensions | RFC 9457, published July 2023, replaces RFC 7807. Its response body adds context without replacing HTTP status. These members are possible, not universally mandatory; incorrectly typed members are ignored under the specification. |
| Retry-After: respect the response without inventing a universal quota | 429 · 503 · Retry-After: 120 · Retry-After · delay-seconds · Scope | Separate call duration from requested retry delay. RFCs 6585 and 9110 define status and Retry-After, not one quota for every service. Numeric examples below are HTTP documentation examples, not observations of a queried site. |
| OpenAlex paging: follow the October 2026 contract | per_page · per_page=200 · page × per_page · cursor=* · meta.next_cursor · End · Authentication | Official documentation updated 14 October 2026 and checked 22 October specifies current limits. These rules apply to OpenAlex, not automatically Crossref or harvesting protocols. Preserve documentation vintage with extraction. |
| Crossref: a short page can finish traversal despite a cursor | rows · rows=0 · cursor=* · message.next-cursor · message.items.length < rows · Index changes | Crossref works paging follows service rules checked 22 October 2026. Documentation uses actual returned item counts for stopping. Do not copy OpenAlex termination: field names and contracts differ. |
| OAI-PMH: resume harvesting without losing dates or deletions | datestamp · from · until · granularity · resumptionToken · completeListSize · header status="deleted" · deletedRecord · Protocol example | OAI-PMH 2.0 distinguishes items, metadata formats and disseminated records. Document version 8 January 2015 defines date selection and partial-list resumption. Diagram counts are protocol examples, not measured HAL or OpenAIRE totals. |
| JSON Pointer: distinguish missing, zero and null | "" · / · ~1 · ~0 · /items/0 · /items/01 · /items/- · #/a~1b | RFC 6901 addresses a value inside JSON. It is neither JSONPath nor a modification operation. The reader uses a small invented teaching document, not real observations, distinguishing resolved value, missing path and invalid syntax. |
| Mean and median: revisit the 90-value NIST example | n · mean · median · min · max · Variable | COMPARE-7_1_6.DAT contains the NIST outlier demonstration’s 90 values. Ordered data were checked 22 October 2026. This is a documented teaching dataset, not an income survey or site performance measurement. |
| Quantiles: record the algorithm before comparing software | R quantile · Type 1 · Type 6 · Type 7 · Endpoints · Example Q1 | R documents nine sample-quantile algorithms, with type 7 as default. The NIST 90-value example interpolates at (n + 1)p. Identical files can therefore produce different quartiles without transcription errors. |
| Weights and missing values: preserve value-weight pairs | Weighted mean · Equal weights · Scaling · na.rm · Missing w · Zero weight | State whether weights represent frequency, population or another convention. A formula alone does not make data representative. R weighted.mean() documentation clarifies missing-value behavior for that function, not every library. |
| Spread and uncertainty: distinguish SD from standard error | Sample variance · Sample SD · IQR · Range · SE(mean) · n < 2 | Spread describes observations; estimator uncertainty describes sampling variability within a model. Sharing units does not make them interchangeable. R documents its SD denominator; NIST explains assumptions for mean intervals. |
| Deciles and income shares: distinguish threshold and share ratios | D1 · 2023 · D5 · 2023 · D9 · 2023 · Mean · 2023 · S20 · Insee · S80 · Insee · D9/D1 · (100 − S80)/S20 | Insee’s 18 November 2025 publication reports these 2023 values for mainland France, ordinary housing, non-negative declared household income and a non-student reference person. Annual levels are in 2023 euros. This is a fixed publication snapshot. |
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