What are some examples of minor resonance structures?
Let us discuss the following example:
As it is listed below each resonance structure, there is one major contributor and two minor contributor, but one is listed as "minor" and the second as "very minor". The question is why?
For the "minor" resonance structure, it is minor because of the presence of the formal charges on Oxygen and Nitrogen.
For the "very minor" resonance structure, it is very minor because of the presence of the formal charges and also, because carbon is not obeying the octet rule. It is only surrounded by six electrons.
I hope this helps.