diff --git a/docs/incompatibilities.md b/docs/incompatibilities.md
index 6ee41ba..97e196c 100644
--- a/docs/incompatibilities.md
+++ b/docs/incompatibilities.md
@@ -25,20 +25,20 @@ On data migrations, the linter will show a warning when:
 
 You can ignore checks through the `--exclude-migration-tests` option by specifying any of the codes:
 
-|               Code                |            Description                                               |
-|-----------------------------------|----------------------------------------------------------------------|
-|`NOT_NULL`                         | Not NULL constraint on columns
-|`DROP_COLUMN`                      | Dropping columns
-|`DROP_TABLE`                       | Dropping tables
-|`RENAME_COLUMN`                    | Renaming columns
-|`RENAME_TABLE`                     | Renaming tables
-|`ALTER_COLUMN`                     | Altering columns (could be backward compatible)
-|`ADD_UNIQUE`                       | Add unique constraints
-|`RUNPYTHON_REVERSIBLE`             | RunPython data migration is not reversible (missing reverse code)
-|`RUNPYTHON_ARGS_NAMING_CONVENTION` | By convention, RunPython names two arguments: apps, schema_editor
-|`RUNPYTHON_MODEL_IMPORT`           | Missing apps.get_model() calls for model
-|`RUNPYTHON_MODEL_VARIABLE_NAME`    | The model variable name is different from the model class itself
-|`RUNSQL_REVERSIBLE`                | RunSQL data migration is not reversible (missing reverse SQL)
-|`CREATE_INDEX`                     | (Postgresql specific) Creating an index without the concurrent keyword will lock the table and may generate downtime
-|`DROP_INDEX`                       | (Postgresql specific) Dropping an index without the concurrent keyword will lock the table and may generate downtime
-|`REINDEX`                          | (Postgresql specific) Reindexing will lock the table and may generate downtime
+|               Code                |            Description                                               |    Default type      |
+|-----------------------------------|----------------------------------------------------------------------|----------------------|
+|`NOT_NULL`                         | Not NULL constraint on columns | Error
+|`DROP_COLUMN`                      | Dropping columns | Error
+|`DROP_TABLE`                       | Dropping tables | Error
+|`RENAME_COLUMN`                    | Renaming columns | Error
+|`RENAME_TABLE`                     | Renaming tables | Error
+|`ALTER_COLUMN`                     | Altering columns (could be backward compatible) | Error
+|`ADD_UNIQUE`                       | Add unique constraints | Error
+|`RUNPYTHON_REVERSIBLE`             | RunPython data migration is not reversible (missing reverse code) | Warning
+|`RUNPYTHON_ARGS_NAMING_CONVENTION` | By convention, RunPython names two arguments: apps, schema_editor | Warning
+|`RUNPYTHON_MODEL_IMPORT`           | Missing apps.get_model() calls for model | Error
+|`RUNPYTHON_MODEL_VARIABLE_NAME`    | The model variable name is different from the model class itself | Warning
+|`RUNSQL_REVERSIBLE`                | RunSQL data migration is not reversible (missing reverse SQL) | Warning
+|`CREATE_INDEX`                     | (Postgresql specific) Creating an index without the concurrent keyword will lock the table and may generate downtime | Warning
+|`DROP_INDEX`                       | (Postgresql specific) Dropping an index without the concurrent keyword will lock the table and may generate downtime | Warning
+|`REINDEX`                          | (Postgresql specific) Reindexing will lock the table and may generate downtime | Warning