Turns out that other letters than the A, B... could be there that are non-translateable - "I ett fåtal fall - där mycket specialla skäl funnits - har decimaluppdelningen i ICD-9 ändrats eller kompletterats" - page 12 http://www.socialstyrelsen.se/klassificeringochkoder/Documents/ICD9_KS87_inledning.pdf
Ruijingfang Jiang noted that the HIV-code differs for Sweden