##### 9.3.2.1 Special Characters

`%`
  A register name can optionally be prefixed by a ``%`' character. So register `%r0` is equivalent to `r0` in the assembly code.
`#`
  The presence of a ``#`' character within a line (but not at the start of a line) indicates the start of a comment that extends to the end of the current line.

  Note: if a line starts with a ``#`' character then it can also be a logical line number directive (see Comments) or a preprocessor control command (see Preprocessing).

`@`
  Prefixing an operand with an ``@`' specifies that the operand is a symbol and not a register. This is how the assembler disambiguates the use of an ARC register name as a symbol. So the instruction

                mov r0, @r0

  moves the address of symbol `r0` into register `r0`.

```
  The ````' (backtick) character is used to separate statements on a single line.

`-`
  Used as a separator to obtain a sequence of commands from a C preprocessor macro.