The stanlab and british disp. thai dbol were pink pentagons, with scored edge and line through middle on on side. There are some fakes of these, if you crush with spoon and tab goes to fine powder it is most likely fake. If you take them and dont start getting intense pumps within a week or 2, with heavy workouts and diet, then they are probably bad.
There was also a thread on measuring the width of the tabs, the fakes were slightly smaller, try a search.
The British Dragon are pink pentagons, with scored edge and line through middle, on the other side is the dragon/snake emblem. These are fairly new and are good, I just got 1000, after only 3 days, my pumps were so good, I would be cramping at night, hours after working out.