Definition
TIS carries three distinct legal meanings depending on context. Researchers must determine which meaning applies from surrounding material before proceeding.
1. TIS (Trespass for goods carried away). An abbreviation for the common law pleading form trespass de bonis asportatis — the action available to a plaintiff whose personal property was wrongfully taken and carried away by another. This was a distinct species of trespass, differentiated from trespass to the person or to real property, and governed by its own procedural rules under common law pleading. The full Latin designation is trespass de bonis asportatis; TIS is simply the abbreviation derived from the English description "Trespass, for goods [carried away] ... taken." Found primarily in older practice manuals and pleading treatises.
2. TI or TIS (Tenant Improvement / Tenant Improvement Allowance). In modern commercial real estate practice, TI or TIS commonly refers to the tenant improvement allowance — the sum a landlord agrees to contribute toward the buildout or renovation of leased space to suit a tenant's needs. While "TI" is the more standard abbreviation, "TIS" appears in lease documents and transactional materials as a variant, particularly in clauses addressing improvement schedules, disbursement conditions, or allowance caps.
3. TIS (Truth in Sentencing). A statutory and policy term designating laws requiring convicted offenders to serve a substantial portion — typically 85 percent — of their imposed sentence before becoming eligible for release. Federal truth-in-sentencing provisions and state analogues emerged primarily in the 1990s as part of broader sentencing reform efforts.
Common Language
Modern common usage (Wiktionary): TIS is listed as an initialism for "truth in sentencing" and an acronym for "traffic information system."
Historical common usage: The abbreviation does not appear in Webster's 1913 as an independent entry; it derives from Latin "tis" as an archaic variant of the pronoun "tu" in classical Latin, carrying no relevant legal weight in that form.
The gap that matters: A researcher encountering TIS in a pre-twentieth-century treatise or pleading form is almost certainly looking at the trespass abbreviation, not a sentencing or real estate term. The modern sentencing and real estate uses of TIS/TI are entirely separate developments. Conflating these across periods or subject areas is a genuine research hazard.
Common Confusion
TIS (trespass) and DE BONIS ASPORTATIS are the same concept — one is the English-language abbreviation, the other the Latin pleading formula. Researchers should treat them as interchangeable when tracing historical pleading practice. Neither should be confused with TRESPASS QUARE CLAUSUM FREGIT, which addresses unlawful entry onto land rather than taking of goods.
TI (tenant improvement allowance) and TIS in real estate contexts are functionally identical; the plural or variant form "TIS" in a lease is not a different legal concept.
Why It Matters in Research
The trespass meaning is the meaning you will encounter in the Law Mind historical legal corpus. Black's and Burrill's both define TIS exclusively in the pleading sense, and any nineteenth-century or earlier practice manual using TIS means trespass de bonis asportatis. The cross-reference to Blackstone 3 Bl. Comm. 150–151 and Chitty's Pleadings (1 Chitt. Pl. 171) is the standard citation chain — if you are tracing this action, those sources are your anchors.
Note that Burrill's entry pairs TIS with a reference to tresaiel (also written tresayle), which is the writ of trespass for disturbance of ancestral seisin — a completely different action addressed under a different headword. This juxtaposition in Burrill's is an artifact of alphabetical proximity, not a conceptual connection. Do not infer a relationship.
The Rapalje & Lawrence entry indexed under this source batch returns a definition for SANS FRAIS, which has no connection to TIS; this appears to be a source indexing artifact and should be disregarded for TIS research.
For modern research involving the TI allowance meaning, the Law Mind Real Estate Transactions & Construction Encyclopedia entry on commercial lease negotiation is the relevant corpus resource. The historical dictionaries are silent on this usage entirely — it did not exist as legal terminology when they were written.
Truth-in-sentencing as a legal concept is absent from all three historical dictionaries, which is expected given its mid-to-late twentieth-century statutory origins.
Historical Dictionary Support
Black's Law Dictionary and Burrill's Law Dictionary are in precise agreement on the trespass definition, both pointing to 3 Bl. Comm. 150–151 as authority. Burrill's adds the Chitty citation and cross-references de bonis asportatis explicitly, making it the more useful source for tracing the pleading chain. Neither dictionary addresses TIS as an abbreviation for anything other than this trespass form.
Rapalje & Lawrence does not appear to contain a substantive TIS entry in the available material; the returned content (SANS FRAIS) is likely a source-side indexing error. Researchers should not rely on that source for this term.
All three historical dictionaries reflect a common law pleading world in which the specific form of action determined remedies and procedure — a world abolished by the adoption of code pleading in most American jurisdictions during the nineteenth century and in England by the Judicature Acts of 1873–75. TIS as a standalone pleading term has no operative modern force; it survives only as a historical label.
Jurisdictional Note
The trespass de bonis asportatis action, abbreviated TIS, was a common law form applicable across English and American jurisdictions before code pleading reforms. It has no current procedural significance in any U.S. jurisdiction. Truth-in-sentencing statutes vary significantly by state; the 85-percent federal standard does not apply uniformly across all state systems.
Encyclopedia Cross-Reference
Commercial Lease Negotiation — Key Terms (Rent, Escalation, CAM, TI Allowance, Options), The Law Mind Real Estate Transactions & Construction Encyclopedia