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Reference

Data glossary

Plain-English definitions of the labor, immigration, and crime-data terms behind our APIs. Each term is defined as it's used in US public records and in the Remulous Labs data schemas.

Labor & layoffs

Terms used in LayoffLens (US WARN Act data).

WARN Act

The Worker Adjustment and Retraining Notification (WARN) Act is a 1988 US federal law requiring employers with 100 or more employees to give at least 60 days' advance notice of a mass layoff or plant closure. Notices are filed with state agencies, which publish them publicly.

WARN notice

A single filing made under the WARN Act announcing a specific layoff or closure at a named employer and worksite. It includes the number of employees affected, the notice date, and the effective date.

Mass layoff

Under the WARN Act, a reduction in force at a single site affecting either 500+ employees, or 50–499 employees if they make up at least 33% of the workforce at that site.

Notice date vs. effective date

The notice date is when a WARN filing was submitted; the effective date is when the layoff or closure actually takes effect. The WARN Act requires at least 60 days between them, which is why WARN data is a leading indicator of layoffs.

Provenance

A record of where a piece of data originated. Every Remulous Labs record carries a provenance block — source, source_url, and an ingestion timestamp — linking it back to the official public filing it came from.

Immigration & sponsorship

Terms used in SponsorLens (US DOL labor-certification data).

H-1B

A US non-immigrant visa that lets employers hire foreign workers in specialty occupations requiring a bachelor's degree or higher. Before filing, the employer must submit a Labor Condition Application to the Department of Labor.

PERM

Program Electronic Review Management — the US Department of Labor process for obtaining a permanent labor certification. It is the first step for most employer-sponsored green cards (permanent residency).

Labor Condition Application (LCA)

A form employers file with the Department of Labor before sponsoring an H-1B, H-1B1, or E-3 worker, attesting to the wage offered and the working conditions. It is the basis for much of the public H-1B disclosure data.

Prevailing wage

The minimum wage an employer must pay a sponsored foreign worker for a given occupation in a given area, as determined by the Department of Labor, to avoid undercutting local wages. SponsorLens annualizes it for comparison.

OFLC

The Office of Foreign Labor Certification — the US Department of Labor agency that processes employer applications to hire foreign workers and publishes the quarterly disclosure files that SponsorLens normalizes.

H-2A and H-2B

US temporary visa programs for seasonal foreign labor: H-2A for agricultural work and H-2B for non-agricultural seasonal work such as landscaping, hospitality, and seafood processing.

Crime & public safety

Terms used in UCRLens (FBI UCR crime data).

FBI UCR

The FBI's Uniform Crime Reporting program — the national system through which local law enforcement agencies voluntarily submit crime data, compiled into the official US crime statistics.

Part I offenses

The eight serious crimes the FBI UCR program tracks: murder and non-negligent manslaughter, rape, robbery, aggravated assault, burglary, larceny-theft, motor vehicle theft, and arson.

Return A (RETA)

The FBI UCR master file in which law enforcement agencies report monthly counts of Part I offenses. It is the official federal source for city-level crime data, and what UCRLens parses.

Rate per 100,000

A crime statistic normalized by population — calculated as (offense count ÷ population) × 100,000 — so cities of different sizes can be compared directly. A rate of 500 means 500 offenses per 100,000 residents.

Violent vs. property crime

Two rollups of the Part I offenses. Violent crime covers murder, rape, robbery, and aggravated assault. Property crime covers burglary, larceny-theft, motor vehicle theft, and arson.

Query the data behind these terms

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