Document overwriting of open modes
Document changes made by
@@ -344,6 +344,23 @@ with open('f.txt') as f:
pass
```
+
+### redundant `open` modes
+
+Availability:
+- `--py3-plus` is passed on the commandline.
+
+```python
+open("foo", "U") # open("foo")
+open("foo", "Ur") # open("foo")
+open("foo", "Ub") # open("foo", "rb")
+open("foo", "rUb") # open("foo", "rb")
+open("foo", "r") # open("foo")
+open("foo", "rt") # open("foo")
+open("f", "r", encoding="UTF-8") # open("f", encoding="UTF-8")
+```
+
+
### `OSError` aliases
Availability:
