rencontre tennis 0-based, half-open coordinate system or interbase coordinate system
http://diy-leds.fr/alfanew.PhP7 | A | C | G | T | A | C | G | T | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8
So if you wanted to describe the first base, it would be:
chr 0 1
and GTAC:
chr 2 6
http://biostar.stackexchange.com/questions/7064/bed-coordinates
Update:
Interbase coordinates (top) and base-oriented (below) from Chado Wiki