Short answer. Yes. Rule 130, Section 20 provides that an instrument may be construed according to usage, in order to determine its true character. Established custom or usage in a trade or context can be shown to clarify what the parties actually meant by the document's terms.
What the law says
An instrument may be construed according to usage, in order to determine its true character.
Rule 130, Section 20 — Interpretation according to usage. Read the full provision →
Usage as an interpretive tool
Section 20 permits an instrument to be construed according to usage — established custom or practice, often specific to a trade, locality, or type of transaction. The stated purpose is to determine the instrument's true character, meaning usage helps reveal what the document actually is and means, beyond its bare words. It sits alongside Section 15's rule on peculiar signification, but focuses more broadly on established custom rather than solely on the specialized meaning of individual terms. This differs from varying a document's actual terms; usage supplies context for what already-written words were understood to mean, not a substitute for the parties' own agreement.
How this connects to the other construction rules
This section works alongside the other interpretation provisions in the same part of Rule 130 — rules on peculiar signification of terms, on surrounding circumstances, and on giving effect to all provisions. Usage is one more source of context a court can draw on when construing what an instrument was meant to accomplish. Taken together, these provisions give a court several complementary tools for reading an instrument the way its actual authors and intended audience would have understood it. A court is not limited to any single provision when the meaning of an instrument is unclear; it may weigh usage together with the document's other language and the circumstances surrounding its execution.
Why usage evidence can be decisive
Parties operating within a particular trade or context often write instruments with unstated assumptions shaped by that trade's customary practices. Allowing usage evidence lets a court read the document the way the parties themselves, immersed in that context, would naturally have understood it — rather than reading it in an artificial vacuum. Without room for usage evidence, an instrument drafted within a specialized trade could be misread by a court unfamiliar with that trade's conventions. This is especially valuable for shorthand or technical terms that carry a settled meaning within an industry but would otherwise look ambiguous or incomplete to someone outside that field. The party invoking a particular usage still bears the burden of proving it is genuinely established and known in that trade, rather than a personal or idiosyncratic understanding shared by only one side to the contract.