Is there a list some where of the characters that don't consist of any radicals. For example the left part of 印 isn't made of any radical, if i'm not mistaken. Also there's the left-part of 師. That looks like an incomplete version of the radical 阜. Should i consider the aforementioned left-part to be the same as . They look similar enough to be interchangeable, but being more concerned with reading than informal socializing, i feel it to be of significance. Another example is the top-part of 其.I know that the bottom is 八, but the top sort of, kind of, maybe looks like the radical 甘, but not enough to conclude they're the same. So is the top part of this character something that i have to remember, JUST EXISTS, and is not composed of radicals? If so, is there a list of these "Not-Composed-of-Radicals"character parts?
Thank you