in lib/crawler/data/crawl_result/html.rb [155:168]
def valid_field_name?(field_name)
character_validation = field_name.match?(/\A[a-z0-9_]+\z/) &&
!field_name.start_with?('_') &&
field_name.length <= 64
true unless character_validation == false || Constants::RESERVED_FIELD_NAMES.include?(field_name) == true
end