ðə pɹˈoʊɾəkˌɑːl kˈoʊd fˈiːld ɪz jˈuːzd tə spˈɛsᵻfˌaɪ ðə pɹˈoʊɾəkˌɑːl tˈaɪp ɛŋkˈæpsjʊlˌeɪɾᵻd wɪðˌɪn ðə sˈiː ˌeɪtʃdˌiːˌɛlsˈiː fɹˈeɪm ˈiː.dʒˈiː. zˈiəɹoʊ ˈɛks zˈiəɹoʊˈeɪtzˈiəɹoʊzˈiəɹoʊ fɔːɹ ˈɪntɚnˌɛt pɹˈoʊɾəkˌɑːl.
The Protocol Code field is used to specify the protocol type encapsulated within the cHDLC frame (e.g. 0x0800 for Internet Protocol).