如《韻鏡》嘅每一橫欄嘅四行，由上而下就係一、二、三、四等，從表面上睇就係咁。等係等韻圖嘅一個基本概念，都係等韻學嘅核心。「等」即係對韻母嘅分析又係對聲母和介音嘅分析，非常複雜難於理解，所以下面分條敘述：
For example, the four lines of each horizontal column in "Rhyme Mirror" are one, two, three, four, etc. from top to bottom, which is like this on the surface. Wait is a basic concept of equal rhyme diagram, and it is also the core of rhyme science. "Wait" is the analysis of finals and the analysis of initials and prepositions, which is very complex and difficult to understand, so the following is described in sections: