First I inferred the same thing as interwyrm.
But what brehobit meant was that if you roll 1, 2, 3, 4 or 6 it's what you got; while if you roll 5 you reroll a die and add it to 5. So you can get:
1
2
3
4
6
5+1, 5+2, 5+3, 5+4, 5+6
5+5+1, 5+5+2, 5+5+3, 5+5+4, 5+5+6
5+5+5+1, etc.