The spelling of the word "RTNFALPHA" can be explained using IPA phonetic transcription. The first letter "R" is pronounced as /ɑr/, followed by "T" pronounced as /ti/. The next three letters "NFA" are pronounced as /ɛnfɑ/, and then "L" as /ɛl/ and "P" as /pi/. Finally, "H" is pronounced as /eitʃ/ and "A" as /eɪ/. Putting all these sounds together, the word "RTNFALPHA" is pronounced as /ɑr ti ɛnfɑ ɛl pi eitʃ eɪ/.