How does one form the second person plural polite personal pronoun in Finnish?

As I am trying to study Finnish on my own, I see that for the second person plural informal uses a lowercase t while the polite form uses a capital T. Is this standard in Finnish? Is it a definite rule or does one not distinguish? And if there is, even in the middle of a sentence, does one capitalize the T? As in "Miss� Te manette"? I have looked around but get no concrete answers.