| Abbreviation | Definition |
|---|---|
| NLTC | National Leadership Training Conference |
| NMEC | National Maintenance Engineering Conference |
| NMHCC | National Managed Health Care Conference |
| NMTC | National Music Theater Conference |
| NMUM | Neutron and Muon User Meeting |
| NMUNC | National Model United Nations Conference |
| NMW | National Midwinter Convention |
| NNDC | National Nutrient Databank Conference |
| NNEC | National Nursing Ethics Conference |
| NNEC | Northern New England Conference |
| NNSP | IEEE Workshop on Neural Networks for Signal Processing |
| NNTC | National No Tillage Conference |
| NNTD | National Nanny Training Day |
| NOAC | National Older Adult Conference |
| NOAC | National Order of the Arrow Conference |
| NOCC | New Orleans Convention Center |
| NODC | New Orleans Dental Conference |
| NOEC | National Outdoor Education Conference |
| NOLC | National Orthopaedic Leadership Conference |
| NOMC | NATO Operations Medical Conference |