Numbers from 1 to 10 and numbers identical to the code (such as 24 VQ 24) were not used after 1976. As with the SIV system, The letters I and O were never used because they could be confused with other characters, like 1 and 0. U was excluded as well in 1984, similar to the letter V, but some départements issued registration plates containing that letter until 1991. The letter O was exceptionally used on official cars at the 1992 Winter Olympics in Albertville. Such cars had registration plates with figures between 1 JO 73 and 9999 JO 73. "JO" stands for "Jeux olympiques" while "73" is the code for Savoie where the games took place. Offensive letter combinations, for instance SS, PD, PQ, QQ, KK or WC, were avoided by some either because of historical reasons or because they sound vulgar to French speakers. In the same way, Haute-Garonne did not deliver car plates with "AZF" after the tragic explosion of the AZF factory in Toulouse in 2001. MMM, MMW, MWM and MWW were withdrawn in 1994 because they needed too much space on plates.