| NAK | Negative Acknowledgement |
| NACK | Negative Acknowledge |
| NCI | Negative Chemical Ionization |
| CNV | Contingent Negative Variation |
| NNLS | Non-Negative Least-Squares [Algorithmus] |
| NSI | Negative Surface Ionization |
| INAK | Information Negative Acknowledgement |
| NET | Negative Entropy Trap |
| NTC | Negative Temperature Coefficient |
| NDR | Negative Differential Resistance |
| NTI | Negative Thermionic mass spectrometry |
| NEI | Negative ion with Electron Impact ionization |
| NIDP | Negative Imaginary Decoupling Potential |
| CCNR | Current-Controlled Negative differential Resistance |
| BNPF | Begin Negative Positive Finish [engl.] |
| VCNR | Voltage-Controlled Negative differential Resistance |
| N-MOS | Negative-Channel Metal-Oxide Semiconductor [engl.] Halbleiter-Technologie |
| APNB | Alternative Positive Negative Pressure Breathing [engl.] Methode zur künstlichen Beatmung |
| TOA | Type Of A |
| PT | Packet Type |
| PT | Payload Type |
| PTY | Program Type |
| ST | Segment Type |
| TOS | Type Of Service |
| TE | Type Enforcement |
| FTA | Final Type Approval |
| ITA | Interim Type Approval |
| TAC | Type Approval Code |
| OTF | Open Type Font |
| CTS | Common Type System |
| GTG | Gaussian-Type Geminals |
| DTD | Document Type Definition |
| ETO | Exponential-Type Orbital |
| CGTO | Contracted Gaussian-Type Orbital |
| MTRR | Memory Type Range Register |
| ATM | Adobe Type Manager [engl.] Firmenbezeichnung: Verwaltung von Schriftarten |
| TTF | True-Type-Font [skalierbar] eine Dateiendung |
| UDT | User Defined [Data]type |
| CGTF | Contracted Gaussian-Type Function |
| SNVT | Standard Network Variable Type |
| RTTI | Run Time Type Information / Identification |
| RITA | Reduced Interim Type Approval |
| PTI | Payload Type Identifier / Indicator |
| pfb | Schriftart [Adobe Type Manager] eine Dateiendung |
| ADT | Application Data Type [engl.] |
| tlb | Type-Library [z.B. für COREL od. andere Grafikprg.] eine Dateiendung |
| pfm | Font Metric [Adobe Type Manager] eine Dateiendung |
| qlc | Schrift-Steuerung [Adope Type Manager] eine Dateiendung |
| PNP | Positive Negative Positive [Transistor] |