kˈɑːntɹækt bɹˈɪdʒ bˈɪdɪŋ sˈɪstəmz ɑːɹ mˈeɪnli "nˈætʃɚɹəl" mˈoʊst bˈɪdz hæv ɐn ˈɑːbviəs mˈiːnɪŋ ɔːɹ "ˌɑːɹɾɪfˈɪʃəl" mˈɛni bˈɪdz hæv ɐ mˈiːnɪŋ ˌʌnɹᵻlˈeɪɾᵻd tə ðə dᵻnˌɑːmᵻnˈeɪʃən mˈɛnʃənd.
Contract bridge bidding systems are mainly "natural" (most bids have an obvious meaning) or "artificial" (many bids have a meaning unrelated to the denomination mentioned).