KOI8-U

KOI8-U is an 8-bit character encoding, designed to cover Ukrainian, which uses a Cyrillic alphabet. It is based on KOI8-R, which covers Russian and Bulgarian, but replaces eight graphic characters with four Ukrainian letters Ґ, Є, І, and Ї in both upper case and lower case.

In Microsoft Windows, KOI8-U is assigned the code page number 21866. In IBM, KOI8-U is assigned code page 1168.

KOI8 remains much more commonly used than ISO 8859-5, which never really caught on. Another common Cyrillic character encoding is Windows-1251. In the future, both may eventually give way to Unicode.

KOI8 stands for Kod Obmena Informatsiey, 8 bit (Template:Lang-ru) which means "Code for Information Exchange, 8 bit".

The KOI8 character sets have the property that the Russian Cyrillic letters are in pseudo-Roman order rather than the natural Cyrillic alphabetical order as in ISO 8859-5. Although this may seem unnatural, it has the useful property that if the 8th bit is stripped, the text can still be read (or at least deciphered) in case-reversed transliteration on an ordinary ASCII terminal. For instance, "Русский Текст" in KOI8-U becomes rUSSKIJ tEKST ("Russian Text") if the 8th bit is stripped.

Codepage layout

The following table shows the KOI8-U encoding. Each character is shown with its equivalent Unicode code point and its decimal code point.

KOI8-U

	_0	_1	_2	_3	_4	_5	_6	_7	_8	_9	_A	_B	_C	_D	_E	_F
0_	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|
1_	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|	Template:Chset-color-undef|
2_	Template:Chset-color-punct|SP 0020 32	Template:Chset-color-punct|! 0021 33	Template:Chset-color-punct|" 0022 34	Template:Chset-color-punct|# 0023 35	Template:Chset-color-punct|$ 0024 36	Template:Chset-color-punct|% 0025 37	Template:Chset-color-punct|& 0026 38	Template:Chset-color-punct|' 0027 39	Template:Chset-color-punct|( 0028 40	Template:Chset-color-punct|) 0029 41	Template:Chset-color-punct|* 002A 42	Template:Chset-color-punct|+ 002B 43	Template:Chset-color-punct|, 002C 44	Template:Chset-color-punct|- 002D 45	Template:Chset-color-punct|. 002E 46	Template:Chset-color-punct|/ 002F 47
3_	Template:Chset-color-digit|0 0030 48	Template:Chset-color-digit|1 0031 49	Template:Chset-color-digit|2 0032 50	Template:Chset-color-digit|3 0033 51	Template:Chset-color-digit|4 0034 52	Template:Chset-color-digit|5 0035 53	Template:Chset-color-digit|6 0036 54	Template:Chset-color-digit|7 0037 55	Template:Chset-color-digit|8 0038 56	Template:Chset-color-digit|9 0039 57	Template:Chset-color-punct|: 003A 58	Template:Chset-color-punct|; 003B 59	Template:Chset-color-punct|< 003C 60	Template:Chset-color-punct|= 003D 61	Template:Chset-color-punct|> 003E 62	Template:Chset-color-punct|? 003F 63
4_	Template:Chset-color-punct|@ 0040 64	Template:Chset-color-alpha|A 0041 65	Template:Chset-color-alpha|B 0042 66	Template:Chset-color-alpha|C 0043 67	Template:Chset-color-alpha|D 0044 68	Template:Chset-color-alpha|E 0045 69	Template:Chset-color-alpha|F 0046 70	Template:Chset-color-alpha|G 0047 71	Template:Chset-color-alpha|H 0048 72	Template:Chset-color-alpha|I 0049 73	Template:Chset-color-alpha|J 004A 74	Template:Chset-color-alpha|K 004B 75	Template:Chset-color-alpha|L 004C 76	Template:Chset-color-alpha|M 004D 77	Template:Chset-color-alpha|N 004E 78	Template:Chset-color-alpha|O 004F 79
5_	Template:Chset-color-alpha|P 0050 80	Template:Chset-color-alpha|Q 0051 81	Template:Chset-color-alpha|R 0052 82	Template:Chset-color-alpha|S 0053 83	Template:Chset-color-alpha|T 0054 84	Template:Chset-color-alpha|U 0055 85	Template:Chset-color-alpha|V 0056 86	Template:Chset-color-alpha|W 0057 87	Template:Chset-color-alpha|X 0058 88	Template:Chset-color-alpha|Y 0059 89	Template:Chset-color-alpha|Z 005A 90	Template:Chset-color-punct|[ 005B 91	Template:Chset-color-punct|\ 005C 92	Template:Chset-color-punct|] 005D 93	Template:Chset-color-punct|^ 005E 94	Template:Chset-color-punct|_ 005F 95
6_	Template:Chset-color-punct|` 0060 96	Template:Chset-color-alpha|a 0061 97	Template:Chset-color-alpha|b 0062 98	Template:Chset-color-alpha|c 0063 99	Template:Chset-color-alpha|d 0064 100	Template:Chset-color-alpha|e 0065 101	Template:Chset-color-alpha|f 0066 102	Template:Chset-color-alpha|g 0067 103	Template:Chset-color-alpha|h 0068 104	Template:Chset-color-alpha|i 0069 105	Template:Chset-color-alpha|j 006A 106	Template:Chset-color-alpha|k 006B 107	Template:Chset-color-alpha|l 006C 108	Template:Chset-color-alpha|m 006D 109	Template:Chset-color-alpha|n 006E 110	Template:Chset-color-alpha|o 006F 111
7_	Template:Chset-color-alpha|p 0070 112	Template:Chset-color-alpha|q 0071 113	Template:Chset-color-alpha|r 0072 114	Template:Chset-color-alpha|s 0073 115	Template:Chset-color-alpha|t 0074 116	Template:Chset-color-alpha|u 0075 117	Template:Chset-color-alpha|v 0076 118	Template:Chset-color-alpha|w 0077 119	Template:Chset-color-alpha|x 0078 120	Template:Chset-color-alpha|y 0079 121	Template:Chset-color-alpha|z 007A 122	Template:Chset-color-punct|{ 007B 123	Template:Chset-color-punct|| 007C 124	Template:Chset-color-punct|} 007D 125	Template:Chset-color-punct|~ 007E 126	Template:Chset-color-undef|
8_	Template:Chset-color-graph|─ 2500 128	Template:Chset-color-graph|│ 2502 129	Template:Chset-color-graph|┌ 250C 130	Template:Chset-color-graph|┐ 2510 131	Template:Chset-color-graph|└ 2514 132	Template:Chset-color-graph|┘ 2518 133	Template:Chset-color-graph|├ 251C 134	Template:Chset-color-graph|┤ 2524 135	Template:Chset-color-graph|┬ 252C 136	Template:Chset-color-graph|┴ 2534 137	Template:Chset-color-graph|┼ 253C 138	Template:Chset-color-graph|▀ 2580 139	Template:Chset-color-graph|▄ 2584 140	Template:Chset-color-graph|█ 2588 141	Template:Chset-color-graph|▌ 258C 142	Template:Chset-color-graph|▐ 2590 143
9_	Template:Chset-color-graph|░ 2591 144	Template:Chset-color-graph|▒ 2592 145	Template:Chset-color-graph|▓ 2593 146	Template:Chset-color-punct|⌠ 2320 147	Template:Chset-color-graph|■ 25A0 148	Template:Chset-color-graph|∙ 2219 149	Template:Chset-color-graph|√ 221A 150	Template:Chset-color-graph|≈ 2248 151	Template:Chset-color-graph|≤ 2264 152	Template:Chset-color-graph|≥ 2265 153	Template:Chset-color-punct|NBSP 00A0 154	Template:Chset-color-punct|⌡ 2321 155	Template:Chset-color-punct|° 00B0 156	Template:Chset-color-punct|² 00B2 157	Template:Chset-color-punct|· 00B7 158	Template:Chset-color-punct|÷ 00F7 159
A_	Template:Chset-color-graph|═ 2550 160	Template:Chset-color-graph|║ 2551 161	Template:Chset-color-graph|╒ 2552 162	Template:Chset-color-intl|ё 0451 163	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|є 0454 164	Template:Chset-color-graph|╔ 2554 165	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|і 0456 166	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|ї 0457 167	Template:Chset-color-graph|╗ 2557 168	Template:Chset-color-graph|╘ 2558 169	Template:Chset-color-graph|╙ 2559 170	Template:Chset-color-graph|╚ 255A 171	Template:Chset-color-graph|╛ 255B 172	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|ґ 0491 173	Template:Chset-color-graph|╝ 255D 174	Template:Chset-color-graph|╞ 255E 175
B_	Template:Chset-color-graph|╟ 255F 176	Template:Chset-color-graph|╠ 2560 177	Template:Chset-color-graph|╡ 2561 178	Template:Chset-color-intl|Ё 0401 179	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|Є 0404 180	Template:Chset-color-graph|╣ 2563 181	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|І 0406 182	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|Ї 0407 183	Template:Chset-color-graph|╦ 2566 184	Template:Chset-color-graph|╧ 2567 185	Template:Chset-color-graph|╨ 2568 186	Template:Chset-color-graph|╩ 2569 187	Template:Chset-color-graph|╪ 256A 188	style="border-width:3px;border:medium solid black" Template:Chset-color-intl|Ґ 0490 189	Template:Chset-color-graph|╬ 256C 190	Template:Chset-color-punct|© 00A9 191
C_	Template:Chset-color-intl|ю 044E 192	Template:Chset-color-intl|а 0430 193	Template:Chset-color-intl|б 0431 194	Template:Chset-color-intl|ц 0446 195	Template:Chset-color-intl|д 0434 196	Template:Chset-color-intl|е 0435 197	Template:Chset-color-intl|ф 0444 198	Template:Chset-color-intl|г 0433 199	Template:Chset-color-intl|х 0445 200	Template:Chset-color-intl|и 0438 201	Template:Chset-color-intl|й 0439 202	Template:Chset-color-intl|к 043A 203	Template:Chset-color-intl|л 043B 204	Template:Chset-color-intl|м 043C 205	Template:Chset-color-intl|н 043D 206	Template:Chset-color-intl|о 043E 207
D_	Template:Chset-color-intl|п 043F 208	Template:Chset-color-intl|я 044F 209	Template:Chset-color-intl|р 0440 210	Template:Chset-color-intl|с 0441 211	Template:Chset-color-intl|т 0442 212	Template:Chset-color-intl|у 0443 213	Template:Chset-color-intl|ж 0436 214	Template:Chset-color-intl|в 0432 215	Template:Chset-color-intl|ь 044C 216	Template:Chset-color-intl|ы 044B 217	Template:Chset-color-intl|з 0437 218	Template:Chset-color-intl|ш 0448 219	Template:Chset-color-intl|э 044D 220	Template:Chset-color-intl|щ 0449 221	Template:Chset-color-intl|ч 0447 222	Template:Chset-color-intl|ъ 044A 223
E_	Template:Chset-color-intl|Ю 042E 224	Template:Chset-color-intl|А 0410 225	Template:Chset-color-intl|Б 0411 226	Template:Chset-color-intl|Ц 0426 227	Template:Chset-color-intl|Д 0414 228	Template:Chset-color-intl|Е 0415 229	Template:Chset-color-intl|Ф 0424 230	Template:Chset-color-intl|Г 0413 231	Template:Chset-color-intl|Х 0425 232	Template:Chset-color-intl|И 0418 233	Template:Chset-color-intl|Й 0419 234	Template:Chset-color-intl|К 041A 235	Template:Chset-color-intl|Л 041B 236	Template:Chset-color-intl|М 041C 237	Template:Chset-color-intl|Н 041D 238	Template:Chset-color-intl|О 041E 239
F_	Template:Chset-color-intl|П 041F 240	Template:Chset-color-intl|Я 042F 241	Template:Chset-color-intl|Р 0420 242	Template:Chset-color-intl|С 0421 243	Template:Chset-color-intl|Т 0422 244	Template:Chset-color-intl|У 0423 245	Template:Chset-color-intl|Ж 0416 246	Template:Chset-color-intl|В 0412 247	Template:Chset-color-intl|Ь 042C 248	Template:Chset-color-intl|Ы 042B 249	Template:Chset-color-intl|З 0417 250	Template:Chset-color-intl|Ш 0428 251	Template:Chset-color-intl|Э 042D 252	Template:Chset-color-intl|Щ 0429 253	Template:Chset-color-intl|Ч 0427 254	Template:Chset-color-intl|Ъ 042A 255
	_0	_1	_2	_3	_4	_5	_6	_7	_8	_9	_A	_B	_C	_D	_E	_F

In the table above, 20 is the regular SPACE character, and 9A is the NO-BREAK SPACE.

The difference with KOI8-R consists of the positions 0xA4; 0xA6; 0xA7; 0xAD; and 0xB4; 0xB6; 0xB7; 0xBD; which consist of extra letters that don't exist in Russian.

Although RFC 2319 says that character 95 should be U+2219 (∙), it may also be U+2022 (•) to match the bullet character in Windows-1251.

Some references have a typo and incorrectly state that character B4 is U+0403, rather than the correct U+0404. This typo is present in Appendix A of RFC 2319 (but the table in the main text of the RFC gives the correct mapping).

See also

• Ukrainian alphabet

External links

• RFC 2319
• IBM CDRA