Question: We have this declaration in LCD.c:

```
unsigned char LCD[8][64] = {((unsigned char) 0)};

```

And in LCD.h we want to have something like:

```
extern unsigned char LCD[][];

```

We get this error:

```
Error[Pe098]: an array may not have elements of this type

```

Answer: 
You need, at a minimum, to include the right-most column size for a 2-D array. You can declare it like this:

```
extern unsigned char LCD[][64];

```

Otherwise the compiler would not be able to compute the offset after the first row.
sizeof of LCD array will refused if you didn't define the size of the two dimension !

```
sizeof refused : extern unsigned char LCD[][64];
sizeof accepted : extern unsigned char LCD[8][64];

```

it depend what you want !