Definition
A procedural term from former English practice meaning "incidentally" or "without new process." Specifically, it described the method by which a plaintiff could file a declaration against a defendant who was already in the custody of the court — either at the suit of a different plaintiff, or at the suit of the same plaintiff in a separate cause. Because the defendant was already before the court, no new process (writ, summons, or other initiating mechanism) was required to secure their appearance; the new declaration could be filed against them collaterally, riding the existing custody.
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Common Language
Modern common usage (Wiktionary): Used to introduce a new topic or aside; equivalent to "incidentally" or "by the way."
Historical common usage (Webster's 1913): No discrete entry; the phrase carries its ordinary colloquial sense of something said in passing, parenthetically, or as a side remark.
The overlap in meaning is real but the legal application is precise in a way the common phrase is not. In ordinary speech, "by the by" signals a digression — something tangential to the main subject. In legal practice, it described a technically specific procedural shortcut: the ability to file process against a defendant already in custody without initiating new service. The colloquial flavor of the phrase (something done "in passing") maps loosely onto the legal meaning (something done without the full formality of new process), but a researcher encountering it in a historical pleading or court record should not read it as mere informality. It denotes a recognized procedural mechanism, not a casual aside.
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Why It Matters in Research
This term is a pure artifact of historical English common law procedure and will not appear in modern American or English court practice. Researchers are most likely to encounter it in pre-nineteenth-century English court records, plea rolls, writs, and treatises on common law pleading — particularly in contexts involving arrest, custody, and the filing of declarations.
The procedural logic behind the term depends on understanding how early English courts secured defendants. Once a defendant was in the custody of the court (typically through arrest on a prior writ), that custody could serve as the jurisdictional foundation for additional claims without the plaintiff needing to re-arrest or re-serve the defendant. Filing "by the by" was economical and avoided duplicative process — relevant to understanding entries in historical records where declarations appear filed without accompanying process, which might otherwise seem irregular or defective.
Researchers using Law Mind's corpus of historical English legal materials should flag this term as a procedural marker: its presence in a document strongly suggests a multi-plaintiff custody situation or a same-plaintiff, separate-cause scenario. It is not a substantive legal concept but a procedural descriptor, and it may appear without explanation in older sources that assumed reader familiarity with common law pleading conventions.
The term presents no significant jurisdictional variation because it belongs to a procedural world — English common law pleading before modern civil procedure reforms — that has been superseded everywhere. It did not migrate into American practice as a term of art.
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Historical Dictionary Support
Both editions of Black's Law Dictionary are in complete agreement, reproducing the definition with only minor typographical variation. Neither edition provides supporting case citations or treatise references, which suggests the term was understood as sufficiently settled within the tradition of common law pleading commentary to require none.
What the historical dictionaries do not provide is context for why the term fell out of use. The procedural world that gave "by the by" its technical meaning — one built around the centrality of custody, writ-based process, and the in-court declaration — was dismantled by the English Common Law Procedure Acts of the mid-nineteenth century and, in America, by the Field Code reforms beginning in 1848. Once pleading and process were modernized and formalized under rules-based civil procedure, the circumstance that "by the by" described (leveraging existing custody to avoid new process) was absorbed into general procedural rules and the phrase ceased to carry independent technical weight.
Researchers should note that neither Black's edition gestures at this historical trajectory. The definitions treat the term descriptively without flagging its obsolescence, which is typical of Black's treatment of archaic English practice terms.
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