adj cam gear setting

im goin to be takin these gears off soon, so i want to set thme back to 0. heres my question, i didnt put these on so im not real sure. is this mark in green here the 0 mark for the gears? its kinda hard to see, but theres a little indent right where the arrow is pointing.

http://img.photobucket.com/albums/v103/danteisme/green001.jpg

there should definitly been some indicator for making adjustments otherwise how would u know where ur at!! my aem tru times, had a mark and those were on my b16. i would hope those sprockets gave u something to go bye for timing