Jan,

Airfoil TMD data. I assume everything is in radians.

"Attached Center" is that the AOA of the middle of the Cl/Alpha curve, or is it the AOA at which Cl = 0?

For exemple I have an airfoil -7 +14 thus a range of 21deg (to put in radian) so "attached range" is 21deg

The "center" of that curve is at 4deg AoA with Cl of 0.5, is that my "attached center" value, or is it the AOA where Cl =0 (-1deg in this case)?

Also in your graphs on the wiki, for the attached range, the upper graph (alpha) shows that it goes between - and + (thus the number is the full range) on the graph below (with airfoil pict) it is represented as half (once between 0 and minus, and one between 0 and plus). I assumed it's the former.

Stall range is also represented twice, but I believe that is probably correct.