diff --git a/FALSEHOODS.md b/FALSEHOODS.md index f182a095a..348b6aa15 100644 --- a/FALSEHOODS.md +++ b/FALSEHOODS.md @@ -5,6 +5,17 @@ Given how ubiquitous phone numbers are and how long they've been around, it's surprising how many false assumptions programmers continue to make about them. +1. **An individual has a phone number** + + Some people do not own phones, or do not wish to provide you with their + telephone number when asked. Do not require a user to provide a phone number + unless it is essential, and whenever possible try and provide a fallback + to accommodate these users. + +1. **An individual has only one phone number** + + Obviously, this isn't necessarily true. + 1. **A phone number uniquely identifies an individual** It wasn't even that long ago that mobile phones didn't exist, and it was @@ -12,10 +23,6 @@ surprising how many false assumptions programmers continue to make about them. some parts of the world, this is still true, and relatives (or even friends) share a single phone number. -1. **An individual has only one phone number** - - Obviously, this isn't necessarily true. - 1. **Phone numbers cannot be re-used** Old phone numbers are recycled and get reassigned to other people. @@ -54,6 +61,22 @@ surprising how many false assumptions programmers continue to make about them. Some may be dialable only if the caller is a subscriber to a particular telecom company. +1. **You can send a text message to any phone number** + + A lot of people still only have a fixed-line telephone, which typically cannot + send or receive text messages. + + **Tip:** Whenever possible, try and accommodate these + users by calling them with a voice message or voice prompts. Alternatively, + if your service requires sending text messages, verify that the number + can receive text messages after the user provides it. + +1. **Only mobile phones can receive text messages** + + Some service providers support sending and receiving text messages to fixed-line + numbers. There are also online services like Skype that can send and receive + text messages. + 1. **There are only two ways to dial a phone number: domestically and from overseas**