Questions about parity5_plus_5

Would it be possible to get a description of the `parity5_plus_5` dataset? There's several things that are confusing about it for me.
First, there are some duplicate rows, which seems odd. The rows count from 0 to 1023 in binary, and there are 1124 rows in the dataset, meaning there are 100 duplicate rows.

Also, I'm not sure I understand the name of the dataset. The equation for the class label seems to be
```python
data['class'] == data[['Bit_2', 'Bit_3', 'Bit_4', 'Bit_6', 'Bit_8']].sum(axis=1) % 2
```
but I'm not sure what the intuition behind this is or how it relates to the name. I assume there's some simple binary formula behind this, but I don't immediately see it.
Or is it just referring to the fact that the other five bits don't influence the outcome?