To vote and to register as a voter: two different rights treated indistinctly

Literature on comparative constitutional law usually treats two different political rights as one: the right to vote and the right to register as a voter. The same frequently happens with international law. We can assume that those rights are coincidental in many democratic countries, indeed. However, as I posit using Brazil as an example, this is not a conceptual necessity, and differentiating between those rights is recommended for some reasons. Besides the methodological relevance, there are political and social gains in this differentiation. Special requirements to register as a voter, such as deadlines, procedure, place e.g., may apply and restrict political participation even in countries that formally recognize a universal right to vote. To escape the formalistic trap, it is important to check whether these conditions meet a democratic requirement. Also, in young democracies, having the title of a voter means recognition as a citizen, and thus to be treated as free and equal.