The short uniliteral signs are used to write pronunciation guides for logograms, or a character that represents a word, or morpheme, and later on, being used to write foreign words.
ðə ʃˈɔːɹt jˌuːnɪlˈɪɾɚɹəl sˈaɪnz ɑːɹ jˈuːzd tə ɹˈaɪt pɹənˌʌnsɪˈeɪʃən ɡˈaɪdz fɔːɹ lˈɑːɡəɡɹˌæmz, ɔːɹ ɐ kˈæɹɪktɚ ðæt ɹˌɛpɹᵻzˈɛnts ɐ wˈɜːd, ɔːɹ mˈɔːɹfiːm, ænd lˈeɪɾɚɹ ˈɔn, bˌiːɪŋ jˈuːzd tə ɹˈaɪt fˈɔːɹən wˈɜːdz.