ɪt kænˈɑːt biː jˈuːzd fˈɑːloʊɪŋ blˈækwʊd bɪkˈʌz ðə bˈɪd ʌv fˈaɪv ˌɛntˈiː ˈæsks fɔːɹ kˈɪŋz, bˌʌt ɪt kæn biː jˈuːzd fˈɑːloʊɪŋ kjˈuː bˈɪdz ɔːɹ dʒˈɜːbɚ.
It cannot be used following Blackwood because the bid of 5NT asks for kings, but it can be used following cue bids or Gerber.