Change definition of open tag

README.md

@@ -91,7 +91,7 @@ Until the transition is complete, please also assign both a type and tags.
 | `"education"`  | Any challenge analysing education-related data (analysing students' essays, etc)|
 | `"geo"`  | Any challenge analysing geographical data (localisation, mapping, etc)|
 | `"data"`  | Any challenge where the core component is preparing or cleaning data, or creating new benchmark data sets |
-| `"open"`  | Any data can be used, not just data that was given |
+| `"open"`  | Outside data can be used, not just data that was given |
 | `"pvp"`  | 'player-vs-player', i.e. evaluation is done by having competitors battle |
 | `"robotics"`  | Any challenge involving teaching robots skills |
 | `"driving"`  | Any challenge involving self-driving cars |