Référence définition

Reference definition, an act or instance of referring. See more Faire référence à quelque chose, à quelqu'un, s'y rapporter, y avoir trait ; s'y référer, en faire mention. Ouvrage de référence, ouvrage que l'on consulte pour trouver une information précise, en particulier dans le domaine de la langue (dictionnaire, grammaire) ou dans un domaine technique, scientifique Reference definition: Reference to someone or something is the act of talking about them or mentioning them. A... | Meaning, pronunciation, translations and example noun. 1 The action of mentioning or alluding to something. 'They walked in the direction of the barn as he made reference to meeting her models for the project.'. 'The extent to which folk medicine, which I've made reference to, is practiced is a measure of the quality of the medical service available in that community.'. 'It is clear. Define reference. reference synonyms, reference pronunciation, reference translation, English dictionary definition of reference. n. 1. The act of referring to something: filed away the article for future reference. 2. a. Significance for a specified matter; relation or relationship:..

RÉFÉRENCE, subst. fém. I. A. − Action de (se) référer à quelqu'un, à quelque chose. La référence, purement verbale, que parfois je faisais à Dieu dans mes plaidoiries, donnait de la méfiance à mes clients (Camus, Chute, 1956, p. 1528): 1. Si l'acte humain n'a pas une double référence, d'une part à l'histoire dans laquelle il s. In reference to definition is - about or concerning (something or someone) : in relation to. How to use in reference to in a sentence What Is a Reference? References are people who are familiar with your work and willing to share what they know with potential employers. A reference also refers to the content of the information, insights, and experience that another person is willing to share about your work Dictionary.com is the world's leading online source for English definitions, synonyms, word origins and etymologies, audio pronunciations, example sentences, slang phrases, idioms, word games, legal and medical terms, Word of the Day and more. For over 20 years, Dictionary.com has been helping millions of people improve their use of the English language with its free digital services Reference Work includes reference transactions and other activities that involve the creation, management, and assessment of information or research resources, tools, and services. (The following bullets clarify what is meant by terms within the Reference Work definition.

The English Dictionary. WordReference is proud to offer two English dictionaries--the WordReference Random House Learner's Dictionary of American English and the Collins Concise English Dictionary. These prestigious dictionaries contain more than 125,000 words and phrases. If you still cannot find a term, you can ask or search in the forums. reference definition: 1. a mention of something: 2. a writer or a book, article, etc. that is mentioned in a piece of. Learn more Define referenced. referenced synonyms, referenced pronunciation, referenced translation, English dictionary definition of referenced. n. 1. The act of referring to something: filed away the article for future reference. filed away the article for future reference. 2. a. Significance for a specified matter; relation or relationship. référence \ʁe.fe.ʁɑ̃s\ féminin. Action de référer ou de renvoyer d'une chose à une autre, à un texte, à une autorité.. Vous vous sentirez des âmes de dandy en montant le superbe escalier Napoléon III qui mène vers le lounge proprement dit, appelé le Salon Rouge en référence à la couleur des banquettes aux formes origamiques. — (Petit Futé Paris 2017

Reference Definition of Reference at Dictionary

  1. For More Information . Employment References - This webpage provides basic information about providing good references to employers. From the Government of Canada Services for Youth. Where and how to get work references in Canada - This article provides advice on who to use as a reference and how the reference process works. From Canadian Immigrant Magazine
  2. Reference is defined as a mention of a situation. (noun) An example of reference is the mention of a person's religion t... Dictionary Menu. Dictionary The definition of a reference is someone who will give a recommendation for a position on behalf of another
  3. Find 38 ways to say REFERENCE, along with antonyms, related words, and example sentences at Thesaurus.com, the world's most trusted free thesaurus

Reference data management is the process of managing classifications and hierarchies across systems and business lines. This may include performing analytics on reference data, tracking changes to reference data, distributing reference data, and more.For effective reference data management, companies must set policies, frameworks, and standards to govern and manage both internal and external. definition - WordReference English dictionary, questions, discussion and forums. All Free Reference Obligation: The specific underlying debt upon which a credit derivative is based. A reference obligation is issued by the reference entity. It does not represent all the forms of debt.

Earth is a non-inertial reference frame. Explanation: By now, we are aware of the fact that an inertial frame of reference is a reference frame where an object is either moving with a constant velocity or at rest. In such a frame, there is no net force acting on an object as a result the object is not accelerated A cell reference can be used as a variable in a formula. Want to become great at Excel? Follow our 4 week course on the basics of Excel Modelling. Enroll now. A simple reference. The simplest cell reference appears as a simple mention of the referred cell after an equal sign. For example (=C5) refers to the value within cell C5 Terms of reference (TOR) define the purpose and structures of a project, committee, meeting, negotiation, or any similar collection of people who have agreed to work together to accomplish a shared goal.. Terms of reference show how the object in question will be defined, developed, and verified. They should also provide a documented basis for making future decisions and for confirming or.

Définitions : référence, références - Dictionnaire de

  1. SwaggerHub. Design & document all your REST APIs in one collaborative platform. SwaggerHub Enterprise. Standardize your APIs with projects, style checks, and reusable domains
  2. Definition of reference standards in the Definitions.net dictionary. Meaning of reference standards. What does reference standards mean? Information and translations of reference standards in the most comprehensive dictionary definitions resource on the web
  3. Former Employer as a professional reference. A previous employer can provide the best insight into your work ethic. They know what your responsibilities were at your job and how you handled them. 2. Colleague. Someone you worked alongside at a previous job, even if they weren't your boss, can be an excellent reference
  4. A reference work. ( attributive) That which serves as a reference work . The act of referring: a submitting for information or decision. ( semantics) A relation between objects in which one object designates, or acts as a means by which to connect to or link to, another object. (academic writing) A short written identification of a previously.
  5. A reference work. ( attributive) That which serves as a reference work . The act of referring: a submitting for information or decision. ( semantics) A relation between objects in which one object designates, or acts as a means by which to connect to or link to, another object. (academic writing) A short written identification of a previously.
  6. Reference (or background) sources: What they are and when to use them. Use reference books (also called reference or background sources, or resources) to get quick specific facts or information or an overview of a subject.. Some examples of reference sources are: dictionaries, encyclopedias, bibliographies, almanacs, directories, atlases, and handbooks

Reference definition and meaning Collins English Dictionar

  1. A reference number is a unique identifier assigned to any financial transaction including those made using a credit or debit card. This number is created technologically and designated for a.
  2. DRI is the general term for a set of reference values used to plan and assess nutrient intakes of healthy people. These values, which vary by age and sex, include: Recommended Dietary Allowance (RDA): average daily level of intake sufficient to meet the nutrient requirements of nearly all.
  3. The definition of wage and salary workers for earnings purposes is more narrow in scope than the general wage and salary workers definition used with labor force, The reference week usually is the 7-day calendar week (Sunday-Saturday) that includes the 12th of the month, with occasional exceptions described below..

Call by reference ; Definition : While calling a function, when you pass values by copying variables, it is known as Call By Values. While calling a function, in programming language instead of copying the values of variables, the address of the variables is used it is known as Call By References. Argument Reference. Standard C++ Library reference. C Library The elements of the C language library are also included as a subset of the C++ Standard library. These cover many aspects, from general utility functions and macros to input/output functions and dynamic memory management functions Quick Reference. The belief that 'human nature', an individual's personality, or some specific quality (such as intelligence, creativity, homosexuality, masculinity, femininity, or a male propensity to aggression) is an innate and natural 'essence' (rather than a product of circumstances, upbringing, and culture). The concept is. An online source is material you find online. It can be an online newspaper, magazine or television website such as NBC or CNN. Peer-reviewed journals, webpages, forums and blogs are also online.

To confirm accuracy and reproducibility, USP Reference Standards are rigorously tested and evaluated by multiple independent laboratories including USP, commercial, regulatory, and academic labs. We also provide publicly available, official documentary standards for pharmaceutical ingredients in the USP-NF that link directly with our primary. Formatting Conventions in This Reference Each group code listed in this reference is presented by a numeric group code value and a description. All group codes can apply to DXF ™ files, applications (AutoLISP or ObjectARX), or both. When the description of a code is different for applications and DXF files (or applies to only one or the other. A credit reference, just like a referral for a job, is a reference from a trusted source that lenders use to approve an application for loans or credit. Depending on who provides the referral, a.

REFERENCE Definition of REFERENCE by Oxford Dictionary

delusion [dĕ-loo´zhun] a false belief that is firmly maintained in spite of incontrovertible and obvious proof to the contrary and in spite of the fact that other members of the culture do not share the belief. adj., adj delu´sional. bizarre delusion one that is patently absurd, with no possible basis in fact. delusion of control the delusion that. Function call by reference in C. The call by reference method of passing arguments to a function copies the address of an argument into the formal parameter. Inside the function, the address is used to access the actual argument used in the call. It means the changes made to the parameter affect the passed argument A URL for the package's license, often shown in UIs like nuget.org. When uploading a package to nuget.org, the licenseUrl field is limited to 4000 characters.. license. Supported with NuGet 4.9.0 and above. An SPDX license expression or path to a license file within the package, often shown in UIs like nuget.org 0-9. An address or pointer that changes when the target item is moved or the relationship to it has changed. For example, in a spreadsheet, a cell with a relative reference changes its formula.

Reference - definition of reference by The Free Dictionar

reference: The process by which a tribunal sends a civil action, or a particular issue in the action, to an individual who has been appointed by the tribunal to hear and decide upon it, or to obtain evidence, and make a report to the court. Cross-references Referee Incorporate by Reference Law and Legal Definition. Incorporation by reference is the act of including a second document within another document by only mentioning the second document. This is done by attaching the document to the back of the court papers or contract. This act, if properly done, makes the entire second document a part of the. An absolute cell reference is a cell reference in a spreadsheet application that remains constant even if the shape or size of the spreadsheet is changed, or the reference is copied or moved to another cell or sheet. Absolute cell references are important when referring to constant values in a spreadsheet. Absolute cell reference may also be. Synonyms for reference point include benchmark, yardstick, measure, standard, criterion, touchstone, gauge, barometer, model and basis. Find more similar words at. cross-reference definition: 1. a note in a book that tells you to look somewhere else in the book for more information about. Learn more

What is a reference value? Learn more about Minitab 19. A reference value is the known and correct measurement for each part. The reference value is used for comparison during measurement system analysis. For example, you have a reference part with known weight of 0.025 g that you use to calibrate your scales. Reference values can be determined. Function pass by value vs. pass by reference I will call what you are passing in a to a function the actual parameters, and where you receive them, the parameters in the function, the formal parameters. They are also called actual and formal arguments. When passing parameters, what it is called and what happens can be confusing Absolute references. There may be times when you do not want a cell reference to change when filling cells. Unlike relative references, absolute references do not change when copied or filled.You can use an absolute reference to keep a row and/or column constant.. An absolute reference is designated in a formula by the addition of a dollar sign ($) before the column and row A reference group is a group that we compare ourselves to for the purpose of evaluating our behaviors. Learn more about the different types of reference groups from examples and test your. A reference architecture in the field of software architecture or enterprise architecture provides a template solution for an architecture for a particular domain. It also provides a common vocabulary with which to discuss implementations, often with the aim to stress commonality.A software reference architecture is a software architecture where the structures and respective elements and.

In this article. For workflow definitions in Azure Logic Apps and Power Automate, some expressions get their values from runtime actions that might not yet exist when your workflow starts running. To reference these values or process the values in these expressions, you can use functions provided by the Workflow Definition Language reference interval: distribution of test results that are normal for a selected population of healthy persons. Reference intervals are interpreted according to age, sex, and race. Also called reference range, normal range Reverence is a feeling of deep respect or awe — like what you have for a president, a hero, or a favorite football player A personal reference is a reference provided by an individual who knows you and can vouch for your character and abilities. Most employers require professional references, but personal references may be acceptable if you don't have enough professional references or if the employer specifically requests one. Ask people who know you well, but who. 1. Personal knowledge about the world gained through direct, first-hand involvement in everyday events rather than through representations constructed by other people. It may also refer to knowledge of people gained from direct face-to-face interaction rather than through a technological medium.2. In phenomenology, our situated, immediate, activities and encounters in everyday experience.


The method reference would invoke the method a.compareToIgnoreCase(b). Similarly, the method reference String::concat would invoke the method a.concat(b). Reference to a Constructor. You can reference a constructor in the same way as a static method by using the name new. The following method copies elements from one collection to another A cell reference or cell address is a combination of a column letter and a row number that identifies a cell on a worksheet. For example, A1 refers to the cell at the intersection of column A and row 1; B2 refers to the second cell in column B, and so on. When used in a formula, cell references help Excel find the values the formula should.

A trip is a sequence of two or more stops that occur during a specific time period. Times that a vehicle arrives at and departs from stops for each trip. Service dates specified using a weekly schedule with start and end dates. This file is required unless all dates of service are defined in calendar_dates.txt Reference price is also known as competitive pricing, because here the product is sold just below the price of a competitor's product. Reference price is the cost at which a manufacturer or a store owner sells a particular product, giving a hefty discount compared to its previously advertised price. Description: Reference pricing, in simple. Quick-reference guides are a great way to provide your users and customers with fast and handy instructions for the most common features of your product or service. From screenshots and image editing to templates and image assets, Snagit 2020 makes it incredibly easy to create useful, engaging, and visually appealing quick-reference guide

In Reference To Definition of In Reference To by Merriam

A frame of reference is a complex set of assumptions and attitudes which we use to filter perceptions to create meaning. The frame can include beliefs , schemas , preferences , values, culture and other ways in which we bias our understanding and judgment. Tversky and Kahneman (1981) define a decision frame as 'the decision-maker's. When reference variables are used as formal parameters, this is known as Pass By Reference. void Func2 (int& x, double& y) { x = 12; // these WILL affect the original arguments y = 20.5; } When a function expects strict reference types in the parameter list, an L-value (i.e. a variable, or storage location) must be passed in

Incorporation by Reference. The method of making one document of any kind become a part of another separate document by alluding to the former in the latter and declaring that the former shall be taken and considered as a part of the latter the same as if it were completely set out therein Reference List: Basic Rules. Note: This page reflects the latest version of the APA Publication Manual (i.e., APA 7), which released in October 2019. The equivalent resource for the older APA 6 style can be found here. This resource, revised according to the 7 th edition APA Publication Manual, provides fundamental guidelines for constructing the reference pages of research papers A relative cell reference describes how far away a cell or group of cells is from another cell in the same spreadsheet. When dealing with a spreadsheet formula, the relative cell reference is the default behavior of a formula.For example, to add cells A2 and B2 together you could use the formula =SUM(A2+B2) in cell C2. If you were to copy that formula into cell C3, it would be relative to C3.

This Reference Document has been divided into sections to accurately illustrate how specific parts of the definition are applied, and then how the hierarchal application of the definition is accomplished. Section I is a list of figures. Sections II and III provide illustrative diagrams wit 'Concepts of work in Third World nations were, in the first instance, determined by their own unique cultural frames of reference.' 'The book enacts its communicative efficacy, sometimes at so high a pitch that a gentle reader might seek relief from its relentless demand on visual and verbal and cultural frames of reference - or for a bit of toning down. Cell Reference. A cell reference, or cell address, is an alphanumeric value used to identify a specific cell in a spreadsheet. Each cell reference contains one or more letters followed by a number. The letter or letters identify the column and the number represents the row. In a standard spreadsheet, the first column is A, the second column is. Go To Definition: Click any identifier to go to definition. Find All References: Click the symbol name in definition to find all references. Find References also shows derived types, interface implementations, base members, overriding and overridden members, class instantiations and field or property writes separately. Highlight References Reference Dimension - A dimension, usually without tolerance that is used for information purposes only. It does not govern production or inspection operations. A reference dimension is a repeat of a dimension or is derived from other values on the drawing or related drawings. Symbology: (.250) GD&T Reference & Training Books

Video: References: What Are They

Mixed references can be used to set up formulas that can be copied across rows or columns without the need for manual editing. In some cases (3rd example above) they can be used to create a reference that will expand when copied. Mixed references are a common feature in well-designed worksheets. They are harder to set up, but they make formulas. What's up with all these dictionary reference edits? comes closest but there is a disagreement of opinions there. There is speculation about where Google gets their definitions: some suggest they get them from various other online dictionaries (from leeching the definition from the first dictionary link) The call by reference method of passing arguments to a function copies the reference of an argument into the formal parameter. Inside the function, the reference is used to access the actual argument used in the call. This means that changes made to the parameter affect the passed argument Definition Reference Document . Version 3 | August 2018 . This technical reference was created to assist entities in applying the Bulk Electric System (BES) definition. It should be read in concert with the complete definition, found in the NERC Glossary of Terms, and any guidance issued by the ERO. The process for handling requests for. Difference Between Bibliography and References Bibliography vs References People most of the time do not think that there is any difference between bibliography and references. They often mistake the two to be the same. However, they are different and used in different contexts with each essay or article or book. Bibliography is listing all the materials that have been consulted [

DRL as a level used in medical imaging to indicate whether, in routine conditions, the dose to the patient or the amount of radiopharmaceuticals administered in a specified radiological procedure for medical imaging is unusually high or unusually low for that procedure. Diagnostic reference levels (DRLs) are a practical tool to promote optimization History Americans celebrate Independence Day to commemorate winning their freedom from Great Britain. However, the way they celebrate — and who gets to participate — has changed over time. The History of Independence Day in the U.S. History The Civil Rights Act of 1964 outlawed segregation and ended various forms of employment discrimination Inertial Frame of Reference. At some point in your life, you've probably been on a form of public transportation. It might have been a bus, metro, train, plane, or even something else Reference Sources: Encyclopedias, Dictionaries, Handbooks, and More!: Types of Reference Materials. Do you usually use Wikipedia to get your bearings on a topic? Find even more from authoritative resources using the Library's specialized encyclopedias, dictionaries, and other reference sources

ADVERTISEMENTS: Reference Groups: Important Characteristics of Reference Group! Man is an imitative animal. The desire to imitate other individuals or groups is instinctive in him. When one finds another person progressing in life, he also desires to progress likewise. He compares himself with others and begins behaving like them in order to reach their status [ In 1948 the World Health Organization (WHO) defined health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity (WHO, n.d., para. 1). NB: If you use a direct quote you must use speech marks and include a page or paragraph number In physics, a frame of reference, or reference frame, is a perspective that one uses to determine if an object is moving. A frame of reference consists of an object or environment that is considered to be stationary. Typically the observer is at rest in the reference frame; in this context, the term is observational frame of reference.For example, when you see a ball roll down a street, you. Terms of Reference vs Project Charter. Both terms of reference and project charters are means of defining an initiative. Terms of reference is a far broader term that may apply to an initiative such as negotiations between governments or firms. Project charters are specific to projects, particular projects delivered according to a waterfall model

Dictionary.com Meanings and Definitions of Words at ..

5.3.1 Scope and Usage . The StructureDefinition resource describes a structure - a set of data element definitions, and their associated rules of usage. These structure definitions are used to describe both the content defined in the FHIR specification itself - Resources, data types, the underlying infrastructural types, and also are used to describe how these structures are used in. frame of reference in British English. noun. 1. a set of basic assumptions or standards that determines and sanctions behaviour. 2. any set of planes or curves, such as the three coordinate axes, used to locate or measure movement of a point in space. Collins English Dictionary To do so, click the icon in the top-right corner of the popup and click Open in Find Tool Window. To open the source code of the definition for editing and close the popup, click the icon and then click Edit Source ( F4 ). For markup languages, PyCharm retrieves definitions of symbols from the specified DTD or schema An absolute reference in Excel refers to a reference that is locked so that rows and columns won't change when copied. Unlike a relative reference, an absolute reference refers to an actual fixed location on a worksheet.. To create an absolute reference in Excel, add a dollar sign before the row and column Frames of Reference serve a valuable purpose, because they enable us to take in a wide variety of information, and process it based on our past experience and values. In fact, an individual's Frame of Reference promotes life-stability and quicker decision making. Like individuals, groups also develop a collective Frame of Reference over time

Find comprehensive medical reference information including disease symptoms, diagnoses, treatments, and follow-up; plus drug and medication dosing, interactions, adverse effects, and more on Medscape, a free, comprehensive, and current resource for physicians and other healthcare professionals The Arduino Reference text is licensed under a Creative Commons Attribution-Share Alike 3.0 License.. Find anything that can be improved? Suggest corrections and new documentation via GitHub. Doubts on how to use Github Textual analysis is a research method that requires the researcher to closely analyze the content of communication rather than the structure of the content. A textual analysis is most often used to analyze historical documents and narratives. A textual analysis is valuable in research because it allows researchers to understand meanings and.

Reference Points. Most motion we can see with our eyes. How do we know that something is moving you ask, well it has to do with comparing it to other objects. Motion is hard to detect if you have your eyes closed, because you cannot tell if something is moving by seeing go past something else. Think about a car that has whizze Reference sources are authoritative works that help you locate information about people, facts, and ideas. These sources can help you find the date of an important event, major achievements of an individual or organization, or a definition of a term or concept. These books are often used to find specific facts, rather than written to be read.

Tableau photo lionne en toile, plexi, alu - Tableaux

Definitions of Reference Reference & User Services

Definition and synonyms of point of reference from the online English dictionary from Macmillan Education.. This is the British English definition of point of reference.View American English definition of point of reference.. Change your default dictionary to American English Reference groups can influence an individual's cognitions, affective responses, and behaviors. The many types of reference groups include formal, informal, primary, secondary, membership, aspirational, and dissociative. Combinations of these are possible. (PS - make sure you can describe each type of reference group Creating an Assembly Definition Reference asset. To create an Assembly Definition Reference asset: In the Project window, locate the folder containing the scripts you want to include in the referenced assembly. Create an Assembly Reference asset in the folder (menu: Assets > Create > Assembly Definition Reference). Assign a name to the asset

Croquembouche — WikipédiaEspace pédagogique : enseignements informatiques

WordReference.com Dictionary of Englis

Dietary Reference Intakes (DRIs) are reference values that are quantitative estimates of nutrient intakes to be used for planning and assessing diets for healthy people. They include both recommended intakes and ULs as reference values (see Box 1).Although the reference values are based on data, the data are often scanty or drawn from studies that had limitations in addressing the question Reference frame, also called frame of reference, in dynamics, system of graduated lines symbolically attached to a body that serve to describe the position of points relative to the body.The position of a point on the surface of the Earth, for example, can be described by degrees of latitude, measured north and south from the Equator, and degrees of longitude, measured east and west from the.

Tableau deco en Ligne - Tableau Paysage paradis beach│ HEXOAcompas — WiktionnaireTableau afrique pas cher - Vente de tableaux deco salon

REFERENCE meaning in the Cambridge English Dictionar

A reference map might show bank locations, while a thematic maps shows average income in an area. It's the difference between mapping places and mapping data . This map of poverty from the US Census is a thematic map, concerned with the geography of a demographic phenomenon The reference may be in an abbreviated form according to context-appropriate conventions related to citation metadata. <code> The <code> HTML element displays its contents styled in a fashion intended to indicate that the text is a short fragment of computer code Reference maps show the boundaries and names of geographic areas for which the Census Bureau tabulates statistical data, but do not visualize the data. In some cases, the name is only in the form of a geographic code, such as a census block number. Some types of reference maps show and identify geographic features that are part of the boundary

Referenced - definition of referenced by The Free Dictionar

HTML Reference HTML by Alphabet HTML by Category HTML Browser Support HTML Attributes HTML Global Attributes HTML Events HTML Colors HTML Canvas HTML Audio/Video HTML Character Sets HTML Doctypes HTML URL Encode HTML Language Codes HTML Country Codes HTTP Messages HTTP Methods PX to EM Converter Keyboard Shortcuts Terminal side of an angle - trigonometry. In trigonometry an angle is usually drawn in what is called the standard position as shown above. In this position, the vertex (B) of the angle is on the origin, with a fixed side lying at 3 o'clock along the positive x axis Reference point - International System of Units - Distance - Speed - Average speed - Instantaneous speed - Velocity - Slope - 7.1 An object is in motion if its position changes relative to another object. To decide if you are moving, you can use your chair as a reference point. A reference point is a place or object used for comparison.

référence — Wiktionnair

See Creating an Assembly Definition asset. Define Constraints. Specifies the compiler #define directives that must be defined for Unity to compile or reference an assembly. Unity only compiles and references a Project assembly if ALL of the Define Constraints are satisfied. Constraints work like the #if preprocessor directive in C#, but on the assembly level instead of the script level At baseball-reference.com you'll find, for each player in baseball history, a list of players similar to that player. These lists are generated by a method introduced by Bill James in the 1980s, and his aim was to find players who were similar in quality, but also similar in style of play.. The similar players lists here at pro-football-reference are NOT the same thing EPA's Approach. EPA regulates the emissions from mobile sources by setting standards for the specific pollutants being emitted. EPA established progressively more stringent emission standards for carbon monoxide, hydrocarbons, nitrogen oxides, and particulate matter, starting in the mid-1970s for on-road vehicles and in the early 1990s for nonroad engines and equipment