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: 
With multidimensional arrays, all but the first dimension must be specified. So...

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

```

Should do it.
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 !