import re


def create_user_tags(instring):
    """
    Masks a string with `xxUSER` tags for Twitter-style mentions, IP Addresses, <USER> tags.
    :param instring: The input string.
    :return: Returns those masked version of the string.
    """
    pattern = r"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b|<user>|<USER>|@[A-Za-z0-9_-]*"
    return re.sub(pattern, "xxuser", instring)