| Term | Definition / Meaning / Stand for |
| MMAH |
Ontario Ministry of Municipal Affairs and Housing |
| MNRF |
Ontario Ministry of Natural Resources and Forestry |
| MOHLTC |
Ontario Ministry of Health and Long Term Care |
| MRA |
Mountain Running Adventures |
| MRC |
Mountain Recreation Club |
| MSA |
Mountain Sports Association |
| MSC |
Mountain Sports Camp |
| MTB |
Mountain Bike |
| MTS |
Mountain Trekking Sports |
| MTTC |
Male Tent and Trailer Campers |
| MVSR |
Muskingum Valley Scout Reservation |
| MWA |
Mountain Water Adventures |
| NAA |
National Adventure Association |
| NBR |
National Boating Recreation |
| NCYC |
National Catholic Youth Choir |
| NFA |
National Fishing Association |
| NFC |
National Fitness Club |
| NFP |
National Fishing Programs |
| NFS |
National Forest Service |
| NGC |
National Golf Club |
| NHR |
National Hiking Routes |
| NMC |
National Mountain Climbing |
| NMS |
National Marathon Sports |
| NOC |
National Outdoor Club |
| NPR |
National Park Recreation |
| NPS |
National Park Service |
| NRP |
National Running Program |
| NSC |
National Surfing Club |
| NTA |
National Trekking Association |
| NTC |
National Trail Camping |
| NTR |
National Trekking Routes |
| NWA |
National Water Activities |
| NYMCRA |
New York Marathon Canoe Racing Association |
| OBB |
Outdoor Beach Biking |
| OBT |
Outdoor Biking Trails |
| OC1 |
Outrigger Canoe |
| OCA |
Outdoor Camping Adventures |
| OCF |
Outdoor Camping & Fishing |
| OCR |
Outdoor Canoeing Recreation |
| OCR |
Outdoor Climbing Recreation |
| OMC |
Outdoor Mountain Climbing |
| OMF |
Outdoor Marathon Fitness |
| OPC |
Outdoor Park Camping |
| OQA |
Outdoor Quad Adventures |
| ORC |
Outdoor Recreation Club |
| ORP |
Outdoor Recreational Parks |
| ORV |
Off-Road Vehicle |
| OTF |
Outdoor Trekking Fitness |
| OWC |
Outdoor Water Challenges |
| OWS |
Outdoor Water Sports |
| OWT |
Outdoor Wilderness Trekking |
| PBC |
Public Biking Club |
| PBR |
Public Boating Recreation |
| PBT |
Public Biking Trails |
| PFA |
Public Fishing Association |
| PFS |
Public Fitness Sessions |
| PFT |
Public Fitness Training |
| PGT |
Public Golf Tournament |
| POC |
Public Outdoor Club |
| PPC |
Public Park Camping |
| PRC |
Public Recreation Club |
| PRT |
Public Running Trails |
| PSC |
Public Surfing Club |
| PTA |
Public Trail Association |
| PTS |
Public Trekking Sports |
| PWA |
Public Wilderness Adventures |
| PWF |
Public Wilderness Fitness |
| PWP |
Public Water Park |
| PWQMN |
Provincial Water Quality Monitoring Network |
| PWQO |
Provincial Water Quality Objective |