Fully struck examples with Full Head details bring the most premium. The head is the most weakly struck area of the Standing Liberty Quarter. Other areas important to grading is the high points like the shield and shield rivets, the robe over the midsection, Liberty's left knee and thigh above knee on the obverse.
The reverse high points is the front part of the eagle's wing and feathers.
The more wear in these areas the lesser the grade of the coin, and absences or flattening of these features, due to circulation wear, reveals and even lower a grade.