11.
Apply the CP of the step #10.
Prepare for one valley-fold followed by one mountain-fold.
This two folds is called "inside crimp-fold".
12.
Apply the inside crimp-fold of the step #11.
Prepare for two valley-folds.
When you apply a valley-fold, then the edge will be exactly at the dotted line shown on the left.
Also the edge will be parallel to the crease line shown on the left.