The encodings are based on ISO 646, 7-bit Latiniccharacter encoding standard, and were used in Yugoslavia before widespread use of later CP 852, ISO-8859-2/8859-5, Windows-1250/1251 and Unicode standards. It was named after ASCII, having the first word "American" replaced with "Yugoslav": "Yugoslav Standard Code for Information Interchange". Specific standards are also sometimes called by a local name: SLOSCII, CROSCII or SRPSCII for JUS I.B1.002, SRPSCII for JUS I.B1.003, MAKSCII for JUS I.B1.004. JUS I.B1.002 is a national ISO 646 variant, i.e. equal to basic ASCII with less frequently used symbols replaced with specific letters of Gaj's alphabet. Cyrillic standards further replace Latin alphabet letters with corresponding Cyrillic letters. Љ, Њ, Џ and ѕ correspond to Latin digraphs, and are mapped over Latin letters which are not used in Serbian or Macedonian. YUSCII was originally developed for teleprinters but it also spread for computer use. This was widely considered a bad idea among software developers who needed the original ASCII such as , ], ^, ~, |, \ in their source code. On the other hand, an advantage of YUSCII is that it remains comparatively readable even when support for it is not available, similarly to the Russian KOI-7. Numerous attempts to replace it with something better kept failing due to limited support. Eventually, Microsoft's introduction of code pages, appearance of Unicode and availability of fonts finally spelled sure end of YUSCII.
Codepage layout
Code points remained largely the same as in ASCII to maintain maximum compatibility. Following table shows allocation of character codes in YUSCII. Heavy-bordered entries highlight differences from ASCII when interpreted as Latin based characters. Both Latin and Cyrillic glyphs are shown:
YUSCII should not be confused with the G0 Latin set for Serbian, Croatian and Slovene, or the G0 Cyrillic set for Serbian, defined by World System Teletext. Like YUSCII, these are based on ASCII and are where possible homologous with each other for Serbian letters. However, they make different decisions and consequently are not compatible with YUSCII. Macedonian letters Ќ and Ѓ are also assigned unique positions rather than the same as their Serbian equivalents, whereas the lowercase form of Џ and the Macedonian letter Ѕ are not supported. The WST G0 sets are detailed below for reference. Differences from YUSCII are shown with a heavy green border.