Workflow/Data-selection.md

 In order to select data taken only by commercial ships, excluding 
-specialist ship data sources, such as research vessels a selection criteria has been followed. 
+specialist ship data sources, such as research vessels a selection criteria has been established. 
  
 Data selection rules are shown in following table. Reports require a day of the month present and to be valid (e.g. 30 Feb not used), but data with a missing hour are included for certain `dck` between 1850 and 1872.  
 
@@ -35,9 +35,12 @@ Rule | Action
   Hour missing   | Except for `dck` = 246, 701, 721 
 ** At least one present of  `sst`, `slp`, `at`, `w`, `d`, `ww`, `n`, `wbt`, `dpt`, `vv`, `rh`, `wh`, `nh`, `w1`, `osv` | Exclude reports with no selected variables. 
 
-
- 
-
+The data is group according to the following type of platform:
+- SHIP
+- DRIFT 
+- PLAT
+- COAST
+- MOORED