
Falsehoods Programmers Believe About Phone Numbers (2016) - striking
https://github.com/googlei18n/libphonenumber/blob/master/FALSEHOODS.md
======
segfaultbuserr
I have/had a Facebook account with a phone number. The account was left unused
for a few years. Recently, I used my E-mail to reset its password,
unfortunately, since the account was abandoned for a long time, the system
flagged my activity as "suspicious" automatically, and asks me for
confirmation using my phone number.

But I no longer own that number.

And from the customer Q&A forum, I realized I was not the only one - it is
almost impossible to find an actual human from Facebook to solve this kind of
verification problem.

All I wanted is to delete it, but I can't. Now, my account becomes a zombie,
can't be used, can't be deleted, and has lots of personal information. All
thanks to the falsehoods Facebook programmers believed about phone numbers,
and its non-existent "customer [0]" service.

I've heard Google has similar issues [1], if the machine works, then
everything is fine, until you need a human...

Repeat after me: fxxk Facebook.

[0] because I'm the product, not the customer?

[1]
[https://news.ycombinator.com/item?id=18886804](https://news.ycombinator.com/item?id=18886804),

and read this comment,
[https://news.ycombinator.com/item?id=18887548](https://news.ycombinator.com/item?id=18887548)

~~~
krick
No, as much as I hate Facebook: fuck phone numbers. The idea of using phone
number as a personal identification tool is so bad, I'm struggling to believe
this is not some kind of conspiracy designed for the solely purpose of mocking
the user. It is bad enough that phone numbers exist at all in the eyes of the
end user by the year 2019, 15 years after Skype with user-friendly logins
appeared and when about a half of the planet uses the phone almost solely for
the purpose of having a pocket-size internet access device anyway. But making
phone numbers a passport of sorts (a proprietary, insecure, easy to lose
passport, over which you have basically no control) is the worst, the most
stupid/evil idea ever. And there's no way around it, it is used by (supposedly
"secure") whatsapp, telegram, google, facebook, every fucking pizza delivery
service and, well, basically everything else. And I hate every single person
responsible for helping that happen.

Seriously, I would do everything I can to destroy fucking phone numbers, but I
have no idea how can we stop this madness.

~~~
yesenadam
Well, I don't have a phone - have never had a mobile phone. So..I have other
problems instead I guess. But not that one.

~~~
kome
same, i don't have a phone number. my biggest issue is with one of my two
banks, but the other one works just fine without any cellphone.

~~~
yesenadam
Hi there! I thought it was just me. I do have a couple of older friends aged
70+ without mobiles, but that's all I knew of. :-)

~~~
kome
hi! indeed, i don't know many other people without a cellphone, but it's not
like I ask every time. there should be dozens of us, dozens.

Do you know low tech magazine?
[https://www.lowtechmagazine.com/](https://www.lowtechmagazine.com/)

~~~
yesenadam
Hehehe. No I didn't, thanks, looks fascinating.

------
geuszb
More:

* "A mobile phone knows its phone number." The phone cannot know its own phone number without making a call or sending a text message. Some SIM cards carry an "own phone number" record but it is not authoritative and sometimes inaccurate.

* "A SIM card is permanently assigned to a phone number." SIM cards to phone number relationship can be many:many and change over time.

* "<Social app X> requires phone number to sign up, so we should too." Users actually react very differently when a messaging app asks for their phone number (useful to find contacts) vs a calculator app or a game or an app where they want to be anonymous.

------
techsupporter
Flying Spaghetti Monster I hate that this is real:

> 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.

"Oh but not-mobile-number phone numbers are always fraudulent so we don't
accept them!" Great, I love getting caught in spam traps because I _have_ a
mobile phone...but it is a VoIP-backed system so the numbers show up as VoIP.
(BTW, Verizon's "My Numbers" feature also show up as VoIP numbers, not
mobile.)

Even more annoying: "Oh, but a bunch of people we know who are also technology
professionals happen to use Google Voice / Google Fi so we'll just whitelist
them." Grrr. So now I have to care what my "mobile" provider uses for its
underlying network or just use Google.

And the last one: My credit union just sent out a terms of service update
saying I "cannot use Google Voice, VoIP, or similar numbers with Zelle." OK,
but I already have a number like that registered, what now? "Your Zelle access
is suspended until you give us your mobile number." But that _is_ my mobile
number. "Too bad."

~~~
rsync
It's worth noting that a CLEC (or other provider) _can_ , in fact, denote a
non-mobile number (or block of numbers) as "mobile" so that it can do things
like receive text verifications from short codes (like your bank, or gmail,
uses).

This is expensive and time-consuming, however, and almost no CLEC (or other
such provider) will do it - you have to petition and register your number(s)
with _every single mobile provider_ and get them to accept that these are not
sources of spam, etc.

I have this problem because my main, personal number is actually a twilio
number (as I built my own personal telco within twilio) and this means I
cannot receive validation messages from shortcodes (like a bank). I spoke to
some twilio engineers at Signal and they confirmed that it would indeed be
possible to register twilio numbers as "mobile" but too expensive ...

~~~
arthurfm
> I have this problem because my main, personal number is actually a twilio
> number (as I built my own personal telco within twilio) and this means I
> cannot receive validation messages from shortcodes (like a bank)

Why does Twilio work for me for SMS 2FA? Is it because I m using an '07'
number in the UK?

[https://news.ycombinator.com/item?id=19227631](https://news.ycombinator.com/item?id=19227631)

~~~
rsync
It's possible that your 2FA SMS messages are being sent to you FROM a normal
phone number and not a shortcode ...

The problem is not that I can't do 2FA - that's just SMS messaging. The
problem is, I can't receive messages from a shortcode, which is different than
a normal phone number.

------
JdeBP
I would, from personal experience, construct a quite different list. Some of
mine would be:

* Every other country's telephone numbering is like one's own.

* Every other country's telephone numbering is like that of EU countries, or like the NANP.

* The last 10 digits are the subscriber number.

* Geographic numbers are actually geographic.

* 123456789 is a perfectly fine number to use for test calls.

* STD is exactly like NPA-NXX.

* The leading 1- in NANP long distance form is the country code.

* There are only national and international forms nowadays.

* Users do not use E.164 themselves.

* Emergency numbers are easy to filter out, as it's only one number.

There are also falsehoods that _people_ believe about _telephones_ , which I
would start with:

* When you hear the ringing tone, the other end is already ringing.

* Your ringing tone comes from the other end.

* Every network sends in-band call progress tones.

* It's perfectly fine to use fax over a G.729 'phone.

* DTMF is in-band and universally supported.

* DTMF is out of band and synchronous to media.

* There is only one way that callees reject calls, and it never involves being connected.

* TPC does not need to know the correct physical location of your non-mobile 'phone.

* TPC tracks mobile 'phones through "a GPS chip".

* Calls can only be traced whilst the caller is on the line.

* Caller-ID is unspoofable and works across networks and across countries.

* The callee can always clear calls.

* Only the caller can clear a call.

~~~
pault
> Calls can only be traced whilst the caller is on the line.

You just punched a hole in the plot of every procedural crime drama. :)

~~~
jedimastert
You can add "Calls take a non-trivial amount of time (i.e 60 seconds) to
trace" to that list. It's immediate.

------
newscracker
> 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.

Signal, WhatsApp and Telegram are spectacular design failures on this point
because they assume that every person has a phone number and also that every
person has their own private (non-shared) and unique phone number. Facebook,
Google, etc., require a phone number for verification and believe that it’s
sufficiently adequate to thwart spammers.

The whole “must enter a phone number” phenomenon is a big mess, introduces
privacy issues and excludes many people. None of the companies mentioned above
would agree that excluding people is a goal for them, but they’ve made it so.

~~~
0xADEADBEE
I agree fully. I've no clue why phone numbers a prerequisite for most email
account providers or anything else I have to sign up for. There is no quicker
way to make me bail on a signup flow that to demand something that has nothing
to do with what I'm using. I barely use my phone as it is, so I'm excited to
see what the world will look like for me when I finally eschew it!

~~~
PeterisP
Many services need a process that makes it hard for spammers to create a large
number of accounts. If getting that costs a small number of real customers who
can't use your service, oh well, the need to fight spammers is objectively
more important to them as long as there aren't too many real customers with
such problems.

Requiring phone numbers is a system that works quite reasonable, as _most_
people have a phone number, and it's not that easy (and certainly not free)
for a spammer to get thousands of phone numbers to make thousands of fake
identities.

------
jpatokal
> _In Argentina, to dial a mobile number domestically, the digits "15" need to
> be inserted after the area code but before the local number, and the "9"
> after the country code (54) needs to be removed. This transforms +54 9 2982
> 123456 into 02982 15 123456._

I used to work in telco, so I've seen some pretty wacky format formatting
schemes, but this takes the cake. Who thought this was a good idea!?

------
sonofgod
For a copious list of falsehoods you or other programmers might believe, see
also: [https://github.com/kdeldycke/awesome-
falsehood](https://github.com/kdeldycke/awesome-falsehood)

~~~
danesparza
What a great link! Thanks!

------
DrScump
Note: USA-specific

Not even 20 years ago, before any number could be ported to mobiles, landlines
in some (all?) Baby Bell regions had their prefix determined by geography. In
other words, you could know what "zone" a given phone number was in by its
prefix.

Take Silicon Valley. A (650) 960-xxxx number meant Mountain View. (408)
733-xxxx meant Sunnyvale. Etc.

Zones roughly respected cities, but boundary conditions abounded. If you lived
near the Mountain View / Sunnyvale border, you could be in area code 415
(later 650) or 408.

San Jose had 3 zones. Cupertino was part of SJ1. Fremont / Newark were lumped
and spanned 2 zones. Milpitas was part of SJ2. etc.

You were only guaranteed a local (non-toll) calling area of something like 8
miles, but Pac Bell would give you _all_ of the zone overlap: if _any_ part of
your zone was within that 8 (?) miles of _any_ part of your destination zone,
it was a local (free) call. This meant your actual local range could extend
20+ miles.

I set up PC-based call broadcast systems (the vendor product I used was
"BigmOth" for some membership organizations such that I could send a recorded
message to whatever numbers in a given member roster. By placing two parallel
systems in, say, Sunnyvale and SJ3, I could cover everywhere from Menlo Park
to Los Gatos to Coyote to Fremont Newark zone 1 with _no_ variable phone
costs.

So, I set up a table in my database to join prefixes to zones, and my program
went through the contacts and routed each destination number to the
appropriate calling phone book (I rewrote the phone books after every batch of
database updates). I had one system in my house, and a colleague had one in
his in SJ3. I'd just uploaded his share of the phonebooks and the message
recording binary to his ftp site, leaving him maybe 10 minutes of work for
each cycle's setup.

Thus, I could blast 2-minute messages to members over a 200+ square mile area
for free.

It was really slick. 10 years later, it was irrelevant, as everywhere became a
free call.

~~~
reaperducer
Early BBS networks used to do this, too.

Around 1984 the ARB (named for its author, Arthur Richard Brock, R.I.P.) BBS
system did store-and-forward e-mail from one ARB BBS to the next, covering a
good portion of the New England and Mid-Atlantic states.

Back then toll charges were pretty high, but there were gateway nodes that had
phone numbers which had free calling that spanned area codes and LATAs.

ARBnet was pretty awesome, ran on Commodore 64's, and was a pioneer in public
e-mail, but is now completely forgotten.

~~~
lgp71
Do you know of the latest ARB version ever released? When did Arthur die? I
had no idea that he did :( The last ARB version that I saw was 7.60 but it did
not have PETSCII Color Graphics yet at that version.

------
valgaze
"Falsehoods programmers believe about..."

* Names: [https://www.kalzumeus.com/2010/06/17/falsehoods-programmers-...](https://www.kalzumeus.com/2010/06/17/falsehoods-programmers-believe-about-names/)

* REST APIs: [http://slinkp.com/falsehoods-programmers-believe-about-apis....](http://slinkp.com/falsehoods-programmers-believe-about-apis.html)

* Fonts/typefaces: [https://github.com/RoelN/Font-Falsehoods](https://github.com/RoelN/Font-Falsehoods)

Collection of falsehoods: [https://github.com/kdeldycke/awesome-
falsehood](https://github.com/kdeldycke/awesome-falsehood)

~~~
jhare
Timezooooooones

~~~
Balgair
Tom Scott recently did a good piece on a section of Denmark that constantly
shifts timezones: [https://www.youtube.com/watch?v=yRz-
Dl60Lfc](https://www.youtube.com/watch?v=yRz-Dl60Lfc)

In general, the Earth is a really lousy clock.

------
skunkworker
"Phone numbers are numbers" \- I've come this multiple times integrating phone
numbers into a product.

Currently I just store phone numbers in E.164 format as a string with max
length of 25 just to be safe and index them. This really takes up no
additional space and can easily handle extensions.

I can't tell you how many times I've run into people storing phone numbers
without normalization eg: "(555) 444 - 3333" etc., not understanding that's
hard to compare against, where E.164 = "+15554443333" is much more consistent
and also works with services like twilio etc.

~~~
fyfy18
I assume why they store them as entered is because it's hard to convert them
between formats. In North America you format the number that way, but other
countries do it differently. Maybe the phone number is a local number (without
area code) or maybe it has an extension?

If you are just storing the phone number to display to a user at a later time,
it is a lot simpler just to save it as text field with no validation.

------
sly010
Programmers don't actually believe in such falsehoods, nor do they just decide
to be lazy about implementation. In fact if anything programmers are generally
more aware of such things. A better name for these lists would be "falsehoods
businesses insist on despite their engineers warnings".

~~~
TeMPOraL
Yup.

I mean, every programmer I know considers stuff like this to be very
interesting trivia to learn and apply. But even if you know this stuff,
putting the knowledge to use often involves a series of battles against your
PMs and managers and maybe even customers, who either don't know it, have
their own vision, or just follow what everyone else does.

(Getting a product to work correctly is as much an exercise of diplomacy and
ego management as it is a matter of technical skills.)

~~~
Tor3
I remember a discussion on the Linux kernel list years ago - and I believe
Linus himself at one point insisted that names with less than three characters
shouldn't be accepted, as they must surely be invalid. I pointed out that when
I was a student there was another student with a full name consisting of just
a single letter. No first name, no last name, just that letter. And the best
thing - the student loans bank's system actually handled that. A couple of
times each semester there would be wide fanfold prints on the billboard wall,
with each student's name and information about each student's loan
application. They apparently had no issues with his single-letter name, which
means that the governmental name registration system didn't either. Even
though he was a foreigner, and I've never heard about any native person with
just a single name (not to mention just a single letter).

~~~
MockObject
"MySQL ... Its name is a combination of "My", the name of co-founder Michael
Widenius's daughter..."

I've also met a few "Jo"s in my time.

------
realusername
I would personally add one (maybe I'll do a PR): Phone number formats never
change for a particular country.

Vietnam just removed a few months ago one digit of all the mobile phones
making all the previous number recorded for the country invalid.

~~~
Alterlife
+1 from India.

There's popular app in Bangalore that you can use to rent bicycles. I can't
use it because my phone number (which has a relatively newly released starting
digit series) doesn't pass their signup validation.

So frustrating.

It's frustrating indeed.

~~~
sneak
Related: email validation that doesn’t allow for + in usernames or any of the
newfangled hipster fad TLDs.

------
rukuu001
Hah! I used to do a lot of telco work. This led me to basically assume nothing
about phone numbers.

What got me, was that people working at the telco used to give us requirements
that clearly indicated that the telco people entertained a lot of falsehoods
about phone numbers too!

------
lxmcneill
"Users will only store phone numbers in your product's phone number fields"

Not entirely sure what this point is trying to achieve. Do you read a birthday
field expecting a phone number 99% of the time? Should you read a phone number
field expecting an email address? And at what point in that process did you
decide that not having data validation on both ends was a good idea?

~~~
clort
So since I got a phone I have always used it as my address book (yeah, I
export and back it up). In the early days Android was pretty nice. You can
enter all sorts of things in there; multiple addresses, numbers, company
information, birthdays of friends or other important dates etc..

But latterly, Android just won't do birthday dates. Oh sure, the dates are
still in there and get exported from the database but there is no way to enter
the information or look at it on the phone (I use BirthdayAdapter from F-Droid
which causes a reminder on the day)

I expect that some people just put the birthday of their friend in a phone
number field. In fact I'm pretty sure that millions of people just use random
fields for their own purposes full stop, they just don't care about any of
that.

So the article is saying that it is their phone, don't try to control them. If
information is in the field and you can't parse it? You store it and export it
as received but otherwise ignore it..

------
C1sc0cat
Interesting that Germany breaks the ITU limit of 15 - Germany is the last
country I would have thought of to break ITU specs.

------
sdrothrock
Every time I see one of these lists, I think of this list:
[https://github.com/kdeldycke/awesome-
falsehood](https://github.com/kdeldycke/awesome-falsehood)

It's a general list of "Falsehoods Programmers Believe About . . ." lists.
Names also come up fairly often on HN.

------
bryanrasmussen
IF the description of the falsehood includes the line "Obviously, this isn't
necessarily true." I am going to go out on a limb and suggest that programmers
don't really believe it - at any rate I would like documentation of
programmers believing that people have only one phone number. ¨´

~~~
acheron
"Falsehoods Programmers Believe" Titles Considered Harmful

~~~
bryanrasmussen
The unreasonable effectiveness of considering falsehoods programmers believe
harmful.

------
tomglynch
Repeat after me: After reading this I realise the difficulty in using phone
verification while scaling internationally.

~~~
reaperducer
Not just internationally.

The last time I was in northern New Jersey, Warwick Valley Telephone Company
still supported five digit dialing _across area codes!_

People could dial 4nnnn to be connected to 973-764-nnnn (a New Jersey area
code). They could also dial 6nnnn to be connected to 845-986-nnnn (a New York
area code). There were about 15 different short codes across two area codes.

There are a lot of these little regional telephone quirks across America, and
I think every one of them is awesome.

------
ThePadawan
Between 2004 and 2007, Zurich (Switzerland) also switched dialing prefixes
such that multiple phone numbers in fact referred to the same extension [0].

[0] Wikipedia unfortunately has the description only in German:
[https://de.wikipedia.org/wiki/Ehemalige_Telefonvorwahl_(Schw...](https://de.wikipedia.org/wiki/Ehemalige_Telefonvorwahl_\(Schweiz\)?section=7#01_\(aufgehoben\))

~~~
apk17
Kleinwalsertag. Austrian territory, but only reachable (by road) through
germany. Was connected to german phone network, which changed once telco stuff
got smart enough. Effect: For some time a german and an austrian phone number
reached the same phone.

------
org3432
Here’s my addition:

Phone numbers are of the same length within a country. In Austria phone
numbers vary in length, and the trailing numbers can also can be used be PBXs.

------
ggm
A few of these were new to me. I think people who come to phone numbers before
Internet knew about the ITU decision to adopt a semi-efficient distribution by
size model, so the numbers +x[y[z]] were given out for volume, not order-of-
application. +1 was 'North America' Not the USA in this model.

the +88 and Taiwan is an interesting situation. The phone companies agree to
do efficient routing to the TW IDD but China refuses to formally recognize it
in the ITU. So, its routed optimally, even if the prefix routing should honour
Chinese (mainland) intent according to the model ( _thats how I have heard it.
I don 't know how accurate this is_)

Telefonica runs several mobile operations in LatAM and I am told that numbers
can be somewhat mobile (sorry) across borders.

I also know of AT&T subscribers who are domiciled in Canada and who are
flouting some rules to get the phone roaming behaviours they want.

------
aasasd
> googlei18n

> _Some people do not wish to provide you with their telephone number when
> asked_

Well, you don't say!

Next in the series, “Falsehoods programmers believe about 2fa, or: just use
HOTP/TOTP, dammit.”

~~~
segfaultbuserr
A challenge - try to register a Google account without providing personal
information.

~~~
macintux
Heck, last time I tried to register a Twitter account I couldn’t do so without
a phone number to receive a PIN, and a burner number wouldn’t do it. C’est la
guerre.

~~~
segfaultbuserr
I can answer my original question - Google has been actively blacklisting all
forms of VoIP numbers to their best efforts, so it's almost impossible to
register one account without putting in your personal information.

The last time I've checked it, there's only one workaround - you can purchase
a real phone number connected to a computer from a cryptocurrency freelancer
developer...

Many stories from the U.S media are condemning that the requirements of
personal information online by authoritarian governments are threatening free
speech, etc, meanwhile, in the U.S, big companies have done this voluntarily,
and you need to be a hacker to register a Google account without personal
information, it's just ridiculous.

~~~
angel2
"you can purchase a real phone number connected to a computer from a
cryptocurrency freelancer developer..."

Where do I start looking for such a person? I very much dislike the privacy
aspect of the whole phonenumber game and also the environmental impact of
burner use.

~~~
segfaultbuserr
His name is James Stanley. His personal blog is
[https://incoherency.co.uk/blog/](https://incoherency.co.uk/blog/), and it has
many good articles about privacy and cryptography applications, such as Tor
and IPFS, some has made to the HN homepage. You can obtain such an anonymous
physical phone number from his personal service,
[https://smsprivacy.org/](https://smsprivacy.org/), by paying 0.003 Bitcoin,
at the current market price, about ~12-15 USD, per day. Such a high cost can
be justified by very nature of a physical phone number.

But I have to say that It's not a complete solution, it has its own
limitations. Once a phone number expires, it just expires, and I don't think
you can get your previous number back retroactively... So it can only be used
as a workaround for verification code to register your account. If the service
decides to issue a SMS challenge to you in the future, you'll have my Facebook
problem, as I mentioned in the comment section.

Perhaps I can write to him to see whether he can implement a solution for this
problem.

I don't personally know him, I'm just a reader in the field of security and
privacy, and he happens to have a nice blog and an interesting service.

> _I very much dislike the privacy aspect of the whole phonenumber game and
> also the environmental impact of burner use._

Then, you should also care about the environmental impact of cryptocurrency,
Proof-of-work literally works by burning the energy, and in order the secure
the network, it must burn as much energy as currently available for general
computing.

I personally don't have problem with it, as I think a global consensus
mechanism is genuinely expensive, and merely using it does not directly
contribute to its energy use, but I acknowledge that criticisms based on the
environmental ground has a strong and valid point. Perhaps for you, using a
burner phone is still a better option for your philosophy?

Meanwhile, looking forword to GNU/Taler, an PayPal-like anonymous payment
system, which is not a currency, so it doesn't need to burn energy.

[https://news.ycombinator.com/item?id=10258312](https://news.ycombinator.com/item?id=10258312)

------
PakG1
A lot of people have horror stories about what happens when they lose their
phone number, etc. Concern can be extended to email address. I agree that it's
a valid concern, there needs to be a better way to handle this. I am surprised
that this happens with this crowd though. I would figure this crowd would
update all their relevant stuff when their information changes. I normally do.
But I know that definitely this would still be a problem for ordinary
laypeople, so I'm not trying to blame the victim, and so I'm not sure what my
point is. I guess this is just not an easy problem. I imagine identity theft
would be rampant if the processes and requirements were more relaxed. I don't
know what the solution is. :(

------
nerdbaggy
I think this all lumps into nobody really knowing everything about phone
numbers, email addresses, and time

------
sneak
The biggest widely believed programmer falsehood I run into in practice: that
they are ten digits and always start with +1. It’s right up there with “all
users have a US ZIP code”.

~~~
pbhjpbhj
Well I'm in the UK so my zip is 90210. :0p

~~~
sneak
If you are in the UK, you have a postcode, not a ZIP (which refers
specifically to the Zone Improvement Plan, a project undertaken by the United
States Postal Service).

:p

------
8bitsrule
"It wasn't even that long ago that mobile phones didn't exist, and it was
common for an entire household to share one fixed-line telephone number."

And not long before that, it was common for _several_ homes to share _one_
fixed-line telephone number.

[https://en.wikipedia.org/wiki/Party_line_(telephony)](https://en.wikipedia.org/wiki/Party_line_\(telephony\))

------
claviola
Brazil has changed the rules around the requirement to specify an operator for
domestic long distance calls several years ago:
[https://gizmodo.uol.com.br/anatel-aprova-ligacoes-de-
longa-d...](https://gizmodo.uol.com.br/anatel-aprova-ligacoes-de-longa-
distancia-de-telefone-fixo-sem-codigo-da-operadora/) (link in Portuguese)

------
FabHK
"Every phone number has an area code."

Is the falsehood of the above statement sufficiently evident? I don't see it
listed explicitly. In Hong Kong, for example, phone numbers are just 8 digits
(+852 1234 5678). Some websites/apps insist on an area code, forcing one to
arbitrarily split the number.

------
jbverschoor
Oh.. and about 25 years ago, phone number length was set to 10 digital. All
numbers changed.

------
bmn__
> phones in […] Kosovo may be reached by dialing the country calling code for
> Serbia (+381), Slovenia (+386), or Monaco (+377)

That can't be right. When will Americans learn basic 4th school year
geography?

~~~
smcl
Geography and dialling codes aren’t necessarily aligned. So none of those
countries share a border - it doesn’t mean there was never a weird issue with
international dialling codes at some point (and, after I did a bit of
searching, it seems that there was)

~~~
bmn__
> none of those countries share a border

Precisely. That should give the reader pause to think that there's something
wrong.

You're missing that the author mixed up Monaco with Montenegro (Kosovo's
neighbour) because they sound similar. That's the perennial Austria/Australia
confusion writ small.

~~~
PeterisP
There's no mixup.

Kosovo _has_ numbers that are reachable through Monaco (not Kosovo's
neighbour) country code.

Kosovo does not have numbers that are reachable through Montenegro (Kosovo's
neighbour) country code.

------
superkuh
>1\. An individual has a phone number

Requiring a phone number one way for me to ignore your website or service (ie,
Signal) forever. But if you do it I'm probably not your target demographic
anyway.

~~~
Tepix
Requiring a phone number still reduces fraud a lot.

~~~
justtopost
It also enables it. All while being an ugly friction point for many users.

------
fxfan
I see a lot of hate for companies using phone for verification the real hate
should be directed towards att, Verizon because they are double handedly
setting the entire world back. If a phone doesn't do what they want- they wont
sell it and it will lose a lucrative market.

Phone numbers as they are today should be dead. The world is connected using
internet and there should. Be a new standard for "call identity" which should
be cross region.

------
dang
From 2016:
[https://news.ycombinator.com/item?id=11321236](https://news.ycombinator.com/item?id=11321236)

------
mehrdadn
On a tangent, how do people who use services like Google Voice deal with their
VoIP numbers being rejected for verification by many sites?

------
Jemm
Adding to the list:

Some people want to put phone numbers in their address books but never ever
want to call that person. An example would be to get a name from a number only
caller ID so you know not to answer that call.

A flag beside the number to indicate no outbound calls would be helpful.
(separate flag for no inbound calls)

------
4ad
I'll add a few other falsehoods:

* a SIM card holds only one phone number.

* if a SIM card holds multiple phone numbers, they are from the same country.

------
nitwit005
> An individual has only one phone number

Always feel these lists include things no human actually believes.

~~~
DaiPlusPlus
It’s not that people believe this - it’s just that they don’t think things
through when building something. This point was mention because there are
plenty of CRM/contact-management systems that only have a single phone number
field per contact. Or worse: Outlook, which is expressly marketed as a contact
management tool, with its arbitrary restriction of 3 phone numbers and 3
e-mail addresses per contact - or how all contacts have to have first and last
names (how do I have a “company” contact? Etc). Point is, don’t be like
Outlook.

------
chrisan
I guess I'm just cynical, but I always thought it is the companies who want
your phone number for information gathering/ads/etc and not the programmers
making this choice

------
thefringthing
Here's a good one: All phone numbers can be reached using tone dialing. (I
know of at least one phone number to which one can connect only using pulse
dialing.)

~~~
MockObject
How is that even possible?

~~~
EADGBE
The origins of telecommunications automation.
[https://en.wikipedia.org/wiki/Pulse_dialing](https://en.wikipedia.org/wiki/Pulse_dialing)

------
pkaye
So basically phone numbers are one or more alphanumeric fields.

~~~
saagarjha
You can put symbols in phone numbers.

~~~
pkaye
So basically phone numbers are one or more text fields.

~~~
TeMPOraL
Yup. And unless your product is a PBX, a phone number should be an opaque blob
to you.

------
robertAngst
Alright, guess I'll be using email verification

~~~
lubujackson
Cool, I have a bulletproof regex for that

~~~
colejohnson66
Mail::RFC822::Address?

[http://www.ex-parrot.com/pdw/Mail-RFC822-Address.html](http://www.ex-
parrot.com/pdw/Mail-RFC822-Address.html)

------
chris_wot
Is there a library for addresses? These are even more complicated...

~~~
pbhjpbhj
Addresses have been covered a few times here, try a site search (down in the
footer), some of those convos are interesting.

------
babuskov
Interesting how nobody here is complaining about Apple forcing all developers
to switch to 2FA this month.

They sell it as "more secure" and I read it as "higher chance to get locked
out".

~~~
scrollaway
Dont use SMS 2fa, use TOTP.

~~~
babuskov
Doesn't seem to be supported:

[https://discussions.apple.com/thread/6846658](https://discussions.apple.com/thread/6846658)

------
jaredwiener
A few years ago I discovered that if you have a phone number _and_ an email
address in a contact in your iPhone, iMessage looks for other accounts using
the email address FIRST -- even though its ostensibly replacing SMS, which of
course is phone number based.

I found this out because someone accidentally put my email address in a
contact (see: [https://xkcd.com/1279/](https://xkcd.com/1279/)) and then
texted me to call out sick. After multiple attempts to explain that I was not
actually her boss, she accused me of stealing the phone number.

That was a fun day.

------
streblo
I find this category of posts ("falsehoods programmers believe about X") to be
patronizing and unhelpful. Most of these lists (this one included) don't give
good explanations and don't have guidelines for how to avoid the problems that
are highlighted. It's usually just a list of condescending gotchas.

~~~
nerdile
I find these helpful when my team is designing a feature that intersects with
this kind of "gotcha" area, and it sets off warnings in my mind, "I know
there's something tricky about this business requirement but I can't put my
finger on it...", these type of lists at least help me identify particular
pitfalls, even if they don't provide solutions, so I can provide specific and
scoped concerns to push back on or clarify the business requirements.

Some people just also really find these fun to think about.

~~~
sneak
Yup! There are lots of things like this, where I don’t have the list
memorized, but I remember that there is a non-trivial, non-obvious list of
considerations to take into account when doing a certain thing in a non-
fragile (and non-discriminatory) way.

A list of these lists might be useful.

