International standards say that either dot or comma is acceptable as decimal separator and thousand separators are optional spaces, typically a half space when properly typeset.

    ISO 31-0 (after Amendment 2) specifies that "the decimal sign is either the comma on the line or the point on the line". This follows resolution 10[1] of the 22nd CGPM, 2003.[2]

    For example, one divided by two (one half) may be written as 0.5 or 0,5.