As specified in GSM 03.38 v7.2, messages being sent as plain text are restricted to the GSM 7-Bit Alphabet which is shown here:
| { | | | } | ~ | ¡ | £ | ¤ | ¥ | § | ¿ | Ä | Å | Æ | Ç | É | Ñ | Ö | Ø | Ü | ß |
| à | ä | å | æ | è | é | ì | ñ | ò | ö | ø | ù | ü | ! | " | # | $ | % | & | ' |
| ( | ) | * | + | , | - | . | / | : | ; | < | = | > | ? | @ | € | [ | Γ | Δ | </td> |
| Θ | Λ | Ξ | Π | ] | Σ | Φ | Ψ | Ω | ^ | _ | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 9 | a | A | b | B | c | C | d | D | e | E | f | F | g | G | h | H | i | I | j |
| J | k | K | l | L | m | M | n | N | o | O | p | P | q | Q | r | R | s | S | t |
| T | u | U | v | V | w | W | x | X | y | Y | z | Z | |||||||
Although most of the GSM 7-Bit Alphabet takes up the space of one character, there are 6 which take up the space of two because they need to be escaped. These are: [ ] € ~ ^ </p>