i think periods are used in europe and some other countries, in australia it was a space and in USA it is comma... the european use of the comma as the decimal place threw me for ages when i first arrived in europe... i do like the european 1 and 7 tho. but the period separator is an abomination, as is the decimal place, since it's also ambiguous for writing a representation of an array of numbers, colons and semicolons make zero sense in programming languages there is a convergence going on towards using underscores and allowing you to write them as constants this way, this makes recognising the whole number as being space/symbol separated, spaces are already a primary scheme for separating symbols in source code where there is no comma or bracket/brace/parenthesis/math symbol between them we are a long way from having a universal standard of plaintext representation though, just go look at what options you can find in spreadsheet apps