The column headers are:

Stock Assessment Area
Description: Stock Assessment Area identifier
Unit:
Type: categorical
Levels: 220
Note: Stock Assessment Areas are individual rivers, except for those areas where fishery catch cannot be assigned to individual rivers. In such cases, rivers are combined to form geographically-coherent groups of rivers. The assessment area "North Harris SAC" includes parts of two Salmon Fishery Districts (Fincastle and Resort).

Assessed
Description: describes if Stock Assessment Area is assessed for the Conservation of Salmon Regulations
Unit:
Type: categorical
Levels: yes, no
Note:

District
Description: Salmon Fishery District identifier
Unit:
Type: categorical
Levels: 106
Note: See “Collecting the Marine Scotland Salmon and Sea Trout Fishery Statistics” {http://www.gov.scot/ISBN/9781805258438}. The assessment area "North Harris SAC" spans two Salmon Fishery Districts (Fincastle and Resort). There are no Stock Assessment Areas in the Gour, Kishorn, Orkney and Sanda Districts.

Region
Description: Scottish Fishery Region
Unit:
Type: categorical
Levels: Clyde Coast, East, Moray Firth, North, North East, North West, Outer Hebrides, Shetland, Solway, West Coast
Note: See “Collecting the Marine Scotland Salmon and Sea Trout Fishery Statistics” {http://www.gov.scot/ISBN/9781805258438}. There are no Stock Assessment Areas in the Orkney region.