• A -- Northern limit of the sounded fricatives "z" and "j" (as written).
• B -- Southern limit of preservation of the "ei" diphtong (below this line it turns [e], but not in Lisbon.
• C -- Southern and occidental limits of the apico-alveolar "s".
• D -- Southern limit of preservation of "ou" diphtong.
• E -- Frontier between "ch" as [t] (north) and [] (south).
• F -- Northern limit of the distinction between [b] and [v].
• G -- western limit of intervocalic "n" and "l" preserved (as luna vs. lua).

Source: 
Nova Gramática do Português Contemporâneo, de Celso Cunha e Lindley Costa.

The large dialectal regioins are subdivided in smaller speach forms, as:

• the speech of Recife region in Pernambuco (PE);
• the speech of the city of Rio de Janeiro (RJ);
• the speech in the interior of the state of São Paulo (SP);
• the speaches in the southern states (PR, SC and RS).