Isn't the encoding described in tidb-internal-2 wrong?

If I didn't get into mistake while reading the source code, when we encodes a key, we put the `table_id` just after the table prefix `b"t"`. That is, the key format are like:
```
t{table_id}_r{record_id}
```
However this article says:
> Key： tablePrefix_rowPrefix_tableID_rowID

It results in that someone (including me) get confused while trying to understand the encoding of keys.