In the Marine we use the following conventions for PR reviewing:  
- **Concept ACK** - agree with the idea and overall concept, but haven't reviewed the code changes or tested them,
- **utACK (untested ACK)** - reviewed and agree with the code changes but haven't actually tested them,
- **Tested ACK** - reviewed the code changes and have verified the functionality or a bug fix, 
- **NACK** - disagree with the code changes/concept, should be accompanied by an explanation.  
