Recently, I have been noticing the use of periods as group separators in phone numbers in the United States. I do not know the development’s reason but list four ideas here:
- Supporters think it is a standard outside of the US. It is not. US-ens frequently do not adhere to standards, but if periods became popular because they think it is a standard yet continue to use inches and feet, then I am lost for words.
- Supporters think it stands out more. Such changes with stylistic basis and disregard for semantics is common in advertisements (note the -ize instead of -ise—the latter is not a standard, either). If advertisers started the period revolution, then others might start. I have also heard people insist it is “prettier”. (note that the period is outside the quote because it belongs there).
- Supporters are trying to prevent bots from obtaining their numbers and calling them with advertisements—at least until the bots’ authors become aware of the changing (non-)convention.
- Supporters are avoiding line breaks. Hyphen-minuses (the legacy hyphen characters from ASCII) are breakable characters, so using them in phone would allow typographical nightmares like:
1-800-
746-663
Non-breaking equivalent characters were added to Unicode to address such issues; use U+2011 for hyphens and U+00A0 for spaces.
I write my phone numbers as a fully qualified, space-separated sequence of digits (+011 209 858 xxx xxx) and recommend that because it is closer to a standard than any other format I have seen.