K (Cá for Brazil and/or Capa for the others) Y( ípsilon for Brasil and/or "i grego" for the others) (W dáblio for Brasil and/or "duplo V" for the others.
Those 3 letters had been removed from the original latin alphabet, used by Portuguese language, but they are now officially back. For portuguese words W works as V, Y as I and K as C (C/CA/CO/CU only) and Q. These latters are also used for native-american words, such as Kaingang and its derivations, including verbs etc. W also works as U for words based on English. They can often be used to express phonetics sounds /K/ as in CAsa /W/ as in faloU.. etc.
There is not relevant difference between the pronunciation of E between Brasil and Portugal, though Portugal has more vowels sounds than Brasil, for instance, "aCção" the C was used to alert that the A has to be pronounced in a different way, which is the Brazilian standard way.. that is one of the reasons why in Brasil you no longer spell "aCção" but "ação".
..Even not being official accepted, you are going to find many words spelled with K in place of C or Q and W working as U. It is not accepted (correct), but is understandable and quite common over the internet.