
    Create a function that validates whether a delivery route code follows the standard pattern of a primary route identifier followed by either two or three delivery zone markers, where the primary identifier must be 'a' and zone markers must be 'b'. The route code validation is essential for proper categorization of urban and suburban delivery zones in the fleet management system.
    

    
import re

def text_match_two_three(text):
    """
    Create a function that validates whether a delivery route code follows the standard pattern of a primary route identifier followed by either two or three delivery zone markers, where the primary identifier must be 'a' and zone markers must be 'b'. The route code validation is essential for proper categorization of urban and suburban delivery zones in the fleet management system.
    

    """
import re

def text_match_two_three(text):
    """
    Create a function that validates whether a delivery route code follows the standard pattern of a primary route identifier followed by either two or three delivery zone markers, where the primary identifier must be 'a' and zone markers must be 'b'. The route code validation is essential for proper categorization of urban and suburban delivery zones in the fleet management system.
    

    """
    patterns = 'ab{2,3}'
    if re.search(patterns, text):
        return True
    else:
        return False