input: Write a Python function named `max_points_in_square` that takes a 2D list `points` and a string `s`. Each element in `points` represents the coordinates of a point, and each character in `s` represents the tag of the corresponding point. The task is to find the maximum number of points that can be contained within a square centered at the origin (0, 0) with edges parallel to the axes, ensuring no two points within the square share the same tag. Return the maximum number of points that meet these criteria. 
  
  Consider the following details:
  - A point is inside the square if it lies within or on the boundaries of the square.
  - The square's side length can be zero.
output: def max_points_in_square(points, s):
      from collections import defaultdict
      
      def in_square(x1, y1, x2, y2, px, py):
          return x1 <= px <= x2 and y1 <= py <= y2
      
      max_points = 0
      n = len(points)
      
      for i in range(n):
          for j in range(n):
              if i == j:
                  continue
                  
              x1, y1 = points[i]
              x2, y2 = points[j]
              
              x_min, x_max = min(x1, 0), max(x2, 0)
              y_min, y_max = min(y1, 0), max(y2, 0)
              
              tags_in_square = defaultdict(bool)
              count = 0
              
              for k in range(n):
                  px, py = points[k]
                  if in_square(x_min, y_min, x_max, y_max, px, py):
                      if not tags_in_square[s[k]]:
                          tags_in_square[s[k]] = True
                          count += 1
                          
              max_points = max(max_points, count)
      
      return max_points