呢啲並毋代表韻圖係用來解釋反切嘅。韻圖中每一種字音只列一個代表字，而代表字又通常係韻書中相映小韻嘅首字，韻圖並毋專文收錄反切上下字，因此喺韻圖中毋見得就能查到想查嘅反切上下字，搵毋到反切字也就無從得知其所屬嘅聲、韻、調等，亦無法知道拼出來的音節如何發音。韻圖的實際功用相當於現代的聲韻調配合表，即如上文所提到嘅悉曇一樣嘅練音表。
This does not mean that the rhyme diagram is used to explain the reverse tangent. The rhyme diagram does not include the reverse cut upper and lower words, so you can not necessarily find the reverse cut upper and lower words in the rhyme map, and if you can't find the reverse cut word, you will not know the sound, rhyme, tone, etc. to which it belongs, nor can you know how to pronounce the spelled syllables. The actual function of the rhyme chart is equivalent to that of the modern tonal coordination table, i.e. the practice table like the Sidham mentioned above.