Can someone tell me if there is something in the manual that forbids corners like the one that appears in the picture? Or if have some specification about that?
http://team1382.com.br/team/wp-content/uploads/2015/02/IMG_7378-e1423579867842.jpg
We would need more specific knowledge on its intended use and location before we could answer that.
That there looks like a wedge used to force those totes from the walls. Just a guess… not a bad idea.
Rule R7 is probably the one that applies here.
The intention of the corner is facilitate to get the toten. And it is positioned in front of the frame.
Renan,
In years with defined bumper rules, this would not have been able to meet the “bumpers must cover a minimum of 8” either side of a corner" rule. There is no bumper requirement this year. No one can make a ruling based on a picture, the Inspector at your event will check this over. From the picture, I don’t think this violates any rule. However as Jim has pointed out, this will be evaluated under R7 and will be observed for any damage to field elements while in competition.
Good point, didn’t think about damaging the field elements. PRetty sure our robot this year would put it through a wall. 
R7 or R8 are the most likely issues, and they are definitely subjective, based on how they are oriented and actuated and used. We had a rather more wicked looking hook on our Ultimate Ascent climber, and didn’t raise any eyebrows.
R7
Protrusions from the ROBOT and exposed surfaces on the ROBOT shall not pose hazards to the ARENA elements (including
the LITTER, RECYCLING CONTAINERS and TOTES) or people
if the ROBOT includes protrusions that form the “leading edge” of the ROBOT as it drives and have a surface area of less than 1 in.sq , it will
invite detailed Inspection. For example, forklifts, lifting arms, or grapplers may be carefully Inspected for these hazards
I noticed that because the totes have slanted sides, totes that are next to each other are already spaced enough to fit a wedge that has a point with a much larger and safer radius. I’d recommend bending it so that the end of the wedge is not a point, but rather a flat surface, perhaps .25 inches wide so you don’t get inspectors thinking its’ too sharp. Basically, make your wedge into a trapezoid instead of a triangle by making the tip blunt and flat.
Point A) I don’t see anything “wrong” with it… it looks like a nicely rounded leading edge. So long as it doesn’t damage field equipment, I wouldn’t have a problem with it.
Point B) I won’t be doing tech inspection at your event so my answer is not particularly useful.
I think the bottom line is that as long as it doesn’t damage the totes or the field, you should be okay.
Jason