The spelling of the word "SICRNI" can be explained using IPA phonetic transcription. The first letter "S" corresponds to the phoneme /s/, the second letter "I" represents the vowel sound /ɪ/, the third letter "C" corresponds to the consonant sound /k/, the fourth letter "R" corresponds to the consonant sound /r/, the fifth letter "N" represents the consonant sound /n/, and the last letter "I" represents the vowel sound /ɪ/. In summary, "SICRNI" is spelled as /sɪkrni/ in IPA phonetic transcription.