diff --git a/FALSEHOODS.md b/FALSEHOODS.md index 5220f540e..95715c270 100644 --- a/FALSEHOODS.md +++ b/FALSEHOODS.md @@ -219,3 +219,19 @@ surprising how many false assumptions programmers continue to make about them. `1-555-123-4567`. This is technically incorrect. To call this number from Japan, where the international call prefix is `010`, one may dial either `+1 555 123 4567` or `010 1 555 123 4567`. + +1. **Users will only store phone numbers in your product's phone number fields** + + Some users use their contact lists to store things like birthdays or other + information. Unless a piece of user-supplied data has actually been verified + to be a phone number, it should be stored as-is as entered by the user. + +1. **Phone numbering plans published by governments or telecoms represent + reality** + + National numbering plans, such as those administered by the + [ITU](http://www.itu.int/oth/T0202.aspx?parent=T0202), represent the + intentions of the government or telecom. These may be published before, + during, or after the actual implementation of numbering plan changes in the + real world. The actual date on which a phone number range becomes active may + not always adhere to official announcements.