NDI

• National Dance Institute, a not for profit organization
• National Democratic Institute for International Affairs
• Northern Digital Incorporated, a provider of 3D tracking systems
• National Datacast Incorporated, the PBS datacasting subsidiary

• Nephrogenic diabetes insipidus, a form of diabetes insipidus due primarily to pathology of the kidney
• Network Device Interface, an IP Video and Audio Protocol developed by NewTek
• Naphthalene diimides, dyes used in chemistry; See Naphthalene tetracarboxylic dianhydride
• New Dietary Ingredient, defined by the Dietary Supplement Health and Education Act of 1994 to be a dietary ingredient not marketed in the United States before October 15, 1994

• Non-Destructive Inspection, in nondestructive testing
• Non-developmental item, in the Federal Acquisition Regulation
• Net disposable income

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