Add some naming conventions

Author: LeoFR

.idea/vcs.xml

@@ -11,7 +11,7 @@ Our styles are based on the excellent [javascript guide from Airbnb](https://git
 ## Exceptions
 
 ### Whitespace
-- Limit your lines to 105 characters. eslint: [max-len](http://eslint.org/docs/rules/max-len).
+- Limit your lines to 100 characters (with a 5 characters tolerance). eslint: [max-len](http://eslint.org/docs/rules/max-len).
  > This ensures readability and maintainability.
 
   ```javascript
@@ -27,4 +27,29 @@ Our styles are based on the excellent [javascript guide from Airbnb](https://git
   ```
 
 ## Naming conventions
-For sure, there are things we'd like to add here.
+### Consistency and disambiguation
+
+As soon as a concept as a name, this name should always be used to refer to that concept, and that name shouldn't be used to refer
+to anything else.
+
+Example: 
+  - A `globalRouteId` is a unique identifier to a route. One should never call it `routeId` since it is another concept (used in the GTFS, 
+  the tGTFS and the bgtfs with different meaning).
+  - A `feed` is an instance of the `transit_production.feeds` table. An `alertFeed` is an instance of the `service_update.alert_feeds` table.
+  
+
+If some external tools/library/api uses the same name for another concept, then at least the foreign name should be prefixed for disambiguation, or even both.
+  - When we match the stops from the GTFS to the stop from some real-time API, we call the first one `gtfsStop` and the second one `apiStop` even if the first one is usually just called stop.
+
+
+### The name should describe the content
+As much as possible:
+- an array of `value` should be called just `values`;
+- an object of `value` index by some `key` should be called `valueByKey`.
+
+As soon as you start to have different representations of the same thing in the same function, disambiguation on the content should be done. For example:
+- `timestampAsMoment` vs `timestampAsString`
+- `stopSequenceAsString` vs `stopSequenceAsInt`
+
+With some reasonable limits, one shouldn't be afraid to have long variable name, and be more afraid of meaningless names. For example:
+- `apiStopByStopIdByTripHeadsignByRouteId` should be still prefered as `dict` or `apiStops`.