Nota bene is a Latin phrase that translates to “note well.” The verb nota is the singular derivation of notare, to note. Commonly abbreviated as N.B., nota bene is used to add emphasis and to direct the reader of a document to take particular care in reading the material that follows. The use of this imperative is the equivalent of writing an explicit instruction to pay close attention. N.B. is a common abbreviation in legal documents, and in academic, scientific, mathematical, and technical writing.
Professors use N.B. to emphasize instructions that a student must follow, in a course syllabus or in a set of lab instructions. A nota bene section is often appended to the end of a set of longer instructions, particularly in academic contexts, to call attention to common procedural mistakes. As an abbreviation in a mathematical or statistical context, N.B. marks points that are fundamental to the proof or to solving a particular problem. In a research report or journal article, N.B. is used to call attention to surprising, confusing, or subtle points that are nonetheless critical to understanding the conclusions drawn from the analysis of the data.
In a legal setting, nota bene is used to mark a section of material that is fundamental to understanding the purpose of the document. It is also useful for drawing the reader's attention to material that is potentially confusing and requires a more in-depth analysis. Material that is particularly complicated or appears on the surface to be counterintuitive or contradictory is often flagged with this abbreviation. When nota bene appears, it acts like a signpost to readers that they should slow down and critically examine the material that follows.
Although this use is not as common, N.B. is also an abbreviation for nulla bona, which translates to “no goods.” This is also an abbreviation used in legal settings, and it is important to use context to understand what N.B. denotes in a particular document. Nulla bona indicates that the defendant in a proceeding had no goods or effects that were of value for seizing assets.
The convention is that nota bene is always abbreviated in capital letters, and is referring to a singular reader. Notate bene, the plural form, is not typically abbreviated. Rather than being used in a written document, notate bene is typically spoken aloud, to instruct a group of listeners to pay close attention to the next part of a speech.