1 | UN/ECE level A |
| As defined in the basic code table of ISO 646 with the exceptions of lower case letters, alternative graphic character allocations and national or application-oriented graphic character allocations. |
2 | UN/ECE level B |
| As defined in the basic code table of ISO 646 with the exceptions of alternative graphic character allocations and national or application-oriented graphic character allocations. |
3 | UN/ECE level C |
| As defined in ISO 8859-1 : Information processing - Part 1: Latin alphabet No. 1. |
4 | UN/ECE level D |
| As defined in ISO 8859-2 : Information processing - Part 2: Latin alphabet No. 2. |
5 | UN/ECE level E |
| As defined in ISO 8859-5 : Information processing - Part 5: Latin/Cyrillic alphabet. |
6 | UN/ECE level F |
| As defined in ISO 8859-7 : Information processing - Part 7: Latin/Greek alphabet. |
7 | UN/ECE level G |
| As defined in ISO 8859-3 : Information processing - Part 3: Latin alphabet. |
8 | UN/ECE level H |
| As defined in ISO 8859-4 : Information processing - Part 4: Latin alphabet. |
9 | UN/ECE level I |
| As defined in ISO 8859-6 : Information processing - Part 6: Latin/Arabic alphabet. |
10 | UN/ECE level J |
| As defined in ISO 8859-8 : Information processing - Part 8: Latin/Hebrew alphabet. |
11 | UN/ECE level K |
| As defined in ISO 8859-9 : Information processing - Part 9: Latin alphabet. |
12 | UN/ECE level X |
| Code extension technique as defined by ISO 2022 utilising the escape techniques in accordance with ISO 2375. |
13 | UN/ECE level Y |
| ISO 10646-1 octet without code extension technique. |