NEC 90.15: informational notes

NEC 90.15 tells you what informational notes are and how they function inside the Code. Short article, big implications. If you've ever argued on a job site about whether a note is enforceable, this is the section that settles it.

What 90.15 Actually Says

NEC 90.15 states that informational notes are explanatory material only. They are not enforceable as Code requirements. The rule itself is brief, but it draws a hard line between what the AHJ can cite you for and what is simply guidance.

Before the 2023 cycle, this concept lived inside 90.5(C). The 2023 NEC pulled it out into its own article, 90.15, to make the distinction cleaner. Same rule, better placement. If you're working from an older codebook, check 90.5(C) for the equivalent language.

The key phrase to remember: informational notes are "explanatory material." They exist to clarify intent, point you to related standards, or give context. They do not create obligations.

How to Spot an Informational Note

Informational notes are clearly labeled in the NEC. They appear indented under the rule they reference, in a different typeface, and begin with the words "Informational Note" in bold. If you don't see that label, you're looking at enforceable Code text.

Some sections stack multiple notes, labeled "Informational Note No. 1," "Informational Note No. 2," and so on. Each one is independent. None of them are mandatory.

• Labeled with bold "Informational Note" header
• Typically set in a different typeface or indent
• Often point to UL standards, NFPA documents, or IEEE references
• May include cross-references to other NEC articles
• Never contain the words "shall" or "shall not" as requirements

Why This Matters on the Job

Inspectors sometimes lean on informational notes to push a particular interpretation. They can use them to explain their reasoning, but they cannot fail your work solely because you didn't follow a note. If you get pushback, ask the inspector to cite the enforceable rule, not the note.

That said, ignoring informational notes is usually a bad move. They often reference standards that the enforceable Code incorporates elsewhere. For example, a note at NEC 110.3(B) points to listing and labeling requirements, and 110.3(B) itself makes listed instructions mandatory. The note is guidance, but the rule it sits under has teeth.

Field tip: when an inspector cites an informational note, don't argue the note. Ask which enforceable section they're enforcing. Nine times out of ten, there's a real rule behind the concern, and getting to it faster saves the callback.

Common Places You'll See Them

Informational notes show up throughout the Code, but a few spots generate the most field questions. Knowing where to expect them helps you read faster and avoid confusing guidance with obligation.

Article 100 definitions often carry notes explaining how terms are used across the Code. Article 110 general requirements use notes to reference installation standards. Article 250 grounding and bonding leans on notes heavily to point you toward IEEE and UL documents. And GFCI/AFCI sections in 210 frequently note which product standards apply.

1. NEC 100: definitions and their context
2. NEC 110.3(B): points to listing and labeling requirements
3. NEC 210.8: GFCI product standards and application guidance
4. NEC 250.4: performance objectives for grounding systems
5. NEC 310.15: ampacity calculation methods and standards
6. NEC 680: pool and spa installation clarifications

Reading the Code Efficiently

When you're hunting for a rule, train your eye to skip past informational notes on the first pass. Read the enforceable text first, get the requirement straight, then come back and read the notes for context if you need it. This saves time and keeps you from confusing a suggestion with a mandate.

If a note references another NFPA standard, a UL standard, or an IEEE document, those external documents are only enforceable if the main Code text explicitly adopts them. A note saying "see NFPA 70E for worker safety" does not make NFPA 70E part of the NEC. It's a pointer, not an adoption.

Field tip: keep a mental separation: if it says "shall," it's law on the job. If it says "Informational Note," it's the Code writers being helpful. Treat them differently or you'll either over-build or miss a real requirement.

When Notes Become Rules

Occasionally, content that lived as an informational note in one cycle gets promoted to enforceable text in the next. The Code-Making Panels review this material every three years, and guidance that proves essential often moves into the rule body. This is one reason to check the latest edition and the Changes to the NEC publication each cycle.

The reverse also happens. Mandatory language that turned out to be overly prescriptive can get softened into a note. Point being, don't assume a note today will stay a note tomorrow, and don't assume text in an older edition holds the same weight in the current one.

Bottom line on 90.15: informational notes explain, they don't enforce. Read them for context, act on the enforceable text, and when an inspector pushes a note, get them to the real rule behind it.