Definition
A circular is a written or printed communication intended for distribution to a large number of recipients in identical or substantially identical terms. In legal contexts, the term carries meaning across several distinct areas:
1. POSTAL LAW. A printed letter or notice that, by its internal evidence, is being sent in the same form to multiple persons. Under postal regulations, a circular may bear handwritten additions — such as the date, the name of the sender, the name and address of the recipient, and typographical corrections — without losing its classification as a circular for mailing-rate purposes. This classification historically determined postage rates and permissible contents under second-class and third-class mail categories.
2. ADMINISTRATIVE AND REGULATORY USE. A document issued by a government agency, department, or administrative body to communicate instructions, interpretations, or policy guidance to a defined class of persons or subordinate offices. Agency circulars often carry quasi-binding authority within their organizational context, though they may not have the force of formal regulations.
3. COMMERCIAL AND SECURITIES USE. A printed or electronic notice distributed to customers, investors, or the public containing offers, announcements, or disclosures. In securities law, a circular may be the functional equivalent of a prospectus or offering document, and its contents can trigger statutory liability for material misstatement or omission.
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Common Language
Modern common usage (Wiktionary): Distributed to a large number of persons; also, of or relating to a circle; moving in a circle; or (in logic) referring back to itself so as to prevent valid reasoning.
Historical common usage (Webster's 1913): Repeating itself; ending in itself; reverting to the point of beginning; hence, illogical and inconclusive — as in "circular reasoning." Also, addressed to a number of persons or places.
The gap between common and legal meaning here is one of emphasis and consequence. In ordinary speech, "circular" most often calls to mind either a geometric shape or the logical fallacy of circular reasoning. In law, neither of those senses is operative. The legal term refers exclusively to the mass-distribution document — a usage that is present in ordinary English but rarely the first meaning that comes to mind. Researchers encountering "circular" in a legal text should not import the logical or geometric connotations.
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Recognized Forms
/SUBTYPES
Treasury Circular / Revenue Circular: Issued by the Treasury Department or revenue authorities to announce policy, interpretive guidance, or rate changes. Historically significant in tax and customs administration.
Agency Circular: An internal or external communication from a regulatory body providing interpretive guidance or procedural instruction. Distinct from a formal rule or regulation in that it typically does not go through notice-and-comment rulemaking.
Postal Circular: The form specifically addressed by postal laws, controlling mailing classification and rate eligibility.
Offering Circular: A disclosure document used in connection with certain securities offerings, particularly those exempt from full Securities Act registration requirements. Functionally analogous to a prospectus.
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Why It Matters in Research
The term's meaning shifts significantly depending on the legal domain in which it appears. A researcher working in nineteenth-century postal law will encounter "circular" as a technical classification with direct consequences for postage rates, permissible handwritten additions, and mail fraud statutes — the postal definition in Anderson's reflects this usage precisely. Crossing into administrative law, the same word describes a form of agency guidance that occupies contested territory between binding rule and informal policy, and its authority will vary depending on the issuing body and era. In securities law, "offering circular" is a term of art with specific regulatory consequences that must be distinguished from looser uses of the word.
Historical sources are inconsistent on where the line falls between a circular and other forms of printed matter. Pre-twentieth century postal cases often turned on whether a document qualified as a circular for mailing purposes — a fact-intensive inquiry that generated a body of administrative rulings. Researchers in that area should be alert to postal classification decisions, not just statutory text.
Because agency circulars sit below formal regulations in the hierarchy of administrative authority, their precedential weight is a recurring research problem. A circular may represent an agency's settled interpretation without having been promulgated as a rule, and courts have varied in how much deference they extend. The distinction between a circular and a regulation, bulletin, or notice is not always linguistically stable across agencies or time periods.
For securities research, the offering circular is now a defined term under Regulation A and related SEC rules, giving it more precise legal content than the generic term would suggest. Researchers should not conflate modern regulatory usage with the older common-law or postal senses.
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Historical Dictionary Support
Anderson's Dictionary of Law provides the most directly useful historical definition for legal research purposes. It correctly identifies two operationally distinct senses: the adjective describing movement or process ("circular mileage"), and the noun denoting the mass-distribution document in postal law. The postal definition is specific enough to be practically useful — it identifies what handwritten material may appear on a postal circular without defeating its classification, a detail that mattered for rate and fraud purposes.
Webster's 1913 reaches the same distribution sense but buries it among geometric and logical meanings. The logical sense — circular reasoning as illogical and inconclusive — dominates Webster's treatment and reflects the word's primary literary and philosophical use in the period. This is a case where the historical general dictionary is less useful than the legal dictionary for legal research, not because Webster's is wrong, but because the legal term of art had developed a technical meaning that general dictionaries did not foreground.
Neither source addresses the securities or modern administrative senses, which developed substantially in the twentieth century. Researchers relying solely on pre-1920 dictionaries for guidance on "offering circular" or "agency circular" will find the definitions incomplete.
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Jurisdictional Note
The postal definition of circular was largely a matter of federal law and Post Office Department regulation. The administrative and offering circular senses are also predominantly federal in origin, though state blue sky laws use "circular" in securities contexts and may define it differently. Researchers working in state securities or administrative law should verify whether the relevant state statute or regulation provides its own definition.
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Encyclopedia Cross-Reference
See Law Mind Encyclopedia — Postal Regulations (for the postal classification sense and associated mail fraud context); Administrative Communications (for agency circulars and their authority within the regulatory hierarchy); Securities Offerings and Disclosure (for the offering circular in federal and state securities law).
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