How to write a pseudocode?

Note that even using conventions of a normal programming language, the pseudocode is intended exclusively for human reading .

At Wikipedia we have the following definition:

  

Pseudocode is a generic way of writing an algorithm, using a simple language ( native to someone who writes it in a way that anyone can understand) know the syntax of any programming language.

With regard to the code snippet written in Portuguese, var identifies the section for declaration of variables that the program will use. In the example in question, the var could be omitted without any problem, the code compiles normally in the Visualg .

Pseudo: "Prefix used in the formation of words to express falsehood or similarity."

A pseudocode imitates a real code, but it is not. It is a representation of an algorithm, which in turn: "... is a finite sequence of well-defined and unambiguous instructions ...".

In the example you put, we could translate from pseudo-code (Portugol) to the Portuguese language like this:

Algoritmo "OlaMundo"{Define o nome do algorítimo como OlaMundo}
var{palavra chave para declarar uma ou mais variáveis nesse caso está vazio é desnecessário e confunde mesmo, se o VisualG precisar disso vazio eu vejo como erro}
inicio{palavra chave para marcar o inicio do algorítimo}
Escreval("Olá, Mundo!"){Escreva na tela Olá, Mundo!}
Fimalgoritmo{palavra chave para marcar o fim do algorítimo}

The actual algorithm in PHP for example would be:

<?php
$variavel = "Olá, Mundo!";//Atribuo a variável uma string Olá, Mundo! 
echo $variavel;//echo é o comando que emite a string passada como argumento
?>

Every language has its documentation, containing its rules.

The VisualG is based on Portugol, see its documentation.

Let's get some definitions before actually answering.

Second Wikipedia :

  

Pseudocode is a generic way of writing an algorithm, using a simple language (native to the writer, so   be understood by any person) without the need to know the   syntax of any programming language.

An example used in schools is the compiler Visualg , which facilitates the illustration of an algorithm, so that all programmers can understand them (regardless of the language they use).

In my time I learned in Pascal, which in the case is, as if it were the English-language Portuguese that resemble a pseudo-code enough.

Pascal:

program OlaMundo;
begin
 WriteLn('Olá, Mundo!');
end.

Visualg:

Algoritmo "OlaMundo"
inicio
Escreval("Olá, Mundo!")
Fimalgoritmo

The example you posted, I believe it is in visualg, and it uses var , for declaration of variables, because the visualg, somehow need to interpret to compile, but in the case of pseudocode, not compilable, the intention is to understand what this is trying to convey, another example:

INÍCIO
VARIÁVEIS
S,C,I,A,MD:Real;
S ← 0;
C ← 0;
PARA I de 1 ATÉ 10 FAÇA PASSO 1
    Escreva "Digite um número: ";
    LEIA A;
    SE A ≥ 0 ENTÃO
         S ← S + A;
         C ← C + 1;
    FIM SE;
FIM PARA;
MD ← S / C;
ESCREVER ("A média é: ", MD);
FIM

Conclusion:
So, it does not matter what syntax you're going to use to write, as long as the recipient is able to understand what you're saying.