First or Second seat don't open 11 HCP with some 4-3-3-3 distributions but will open all other 11 point hands (actually can open 4=3=3=3, 3=4=3=3 but not 3=3=3-4 or 3=3=4=3 due to potential misleading 1NT rebid by opener)
Third Seat point count can be as low as 8 but likely not lower than 9.
3rd/4th Seat use rule of 15 to consider opening
1c is usually 11-17 HCP, exception is 18+ points with 4-4-4-1 or 5-5 in major minor combination
1NT is weak in first and second seat 12-14 HCP
A reverse is limited to 16 or 17 points and can use Lebenshol
Link to 2/1 System
Link to Precision