Dates are usually written differently in the short (numerical) form. Christmas Day 2000, for example, is 25/12/00 or 25.12.00 in the UK and 12/25/00 in the US, although the formats 25/12/2000, 25.12.2000, and 12/25/2000 now have more currency than they had before Y2K. Occasionally other formats are encountered, such as the ISO 8601 2000-12-25, popular among programmers, scientists and others seeking to avoid ambiguity, and to make alphanumerical order coincide with chronological order. The difference in short-form date order can lead to misunderstanding, especially when using software or equipment that uses the foreign format. For example, 06/04/05 could mean either June 4, 2005 (if read as US format), 6 April 2005 (if seen as in UK format) or even 5 April 2006 if taken to be an older ISO 8601-style format where 2-digit years were allowed.