Is there any reason why only lower case letters are used for routing on the internet?
Since this is true, why do I continually get printed links in my e-mail for web adresses which contain capital letters?
URLs are case-insensitive.
Wrong. Domain names (like straightdope.com) are case-insensitive. However, URLs, like http://boards.straightdope.com/sdmb/showthread.php?threadid=80607, are, or are not, depending on the web server.
Microsoft IIS (for NT and Windows 2000 servers) are not case sensitive. UNIX and Linux servers, like Apache, are case sensitive. So, Index.html is a different file than index.html.
Perhaps I didn’t make myself clear. Why are ONLY lower case letters used?
You have to remember when the internet was founded it was used by computer geeks and nerds.
They made a lot of rules for THEM.
You will notice that until Windows 95 the internet was unheard of. Many of the “rules” of the internet we kept simply because the “GEEKS” said this is so.
If you remember back to high school the “GEEKS” were the ones who followed the rules never got in trouble. So this was the ONE area of the world where they controled. So they made the rules and whether or not they made sense they ridiculed those NOT following them.
PCs became more popular than Apples because the Macs appealed to the masses. The geeks like the DOS prompts etc…
But as much as everyone makes fun of and hates Bill Gates if it wasn’t for him how many people could really use a computer with the dos prompts C:\ for every twitch of a mouse.
Is GEEKS some kind of old OS that I know nothing about? I sure hope so, because if it isn’t someone in this thread has got some issues to work on.
BWAHAHAHAHA!!! That’s what you think! We just knew how not to get caught!
Does it count as “getting in trouble” if you get caught by a teacher who lets you get away with it cuz he thinks you’re cool? 
The true reason is that lower case letters fit better through the thinner wires while the bigger, upper case, letters, sometimes get stuck in the thin phone wires. If everybody had cable modems this would not be a problem.
I guess I may be being picky, but routers use IP addresses, which are only numeric. When an Internet packet is sent, it has a source IP address (where it came from), and a destination IP address. Both of these are four-byte fields - that’s the 169.172.46.15 that you sometimes see. The packet comes to a router along the way, which has the unenviable job of looking at the destination address, and sending the same packet out one of its other ports, at full speed, because there’s another packet coming right after that one. Some of the packets routers send and recieve are in a special router language, telling other routers which other routers they’re connected to, and any one router must build up an internal table continuously so that it can very quickly send any incoming packet out in a way that gets it closer to its destination.
Domain Name Service is an application that runs by sending out IP packets, so that the DNS server computers can translate the name you’re looking for into an IP address. Once that translation is done, the rest of the communication is done with numeric IP addresses. It’s traditional for DNS names to be lower-case, because UNIX people have always used lower-case for commands and addresses. This lets you just remember the command “grep” or whatever without having to remember whether it’s capitalized.
There’s nothing wrong with having uppercase letters in a hostname… http://www.YAHOO.COM works just as well as http://www.yahoo.com, and a lot of hostnames actually contain uppercase letters in DNS (128.169.76.192 = OSCAR.WS.UTK.EDU). Lowercase letters are just a tradition.
CurtC hit on it, it’s purely a user-convenience thing for dealing with case-sensitive operating systems. By simply having everything in lower-case, it makes it easier to get to what you want in the first try, without having to remember if this or that was capitalized.
It’s not just tradition, it’s a standard with a purpose, and a useful one at that. Wish more people followed it.
I recall before Windows 95 was released, OS/2 Warp advertised on TV often that you could use it to get on the internet. The commercials were on fairly often, and everyone seemed to know what the “internet” was already.
As for rules, they were made by people trying to standardize things, as an internet that doesn’t have any standards is rather pointless. Yes, we still keep many of those rules, but the main reason is that changing the rules would require lots of software changes.
To take an example, email uses rather archaic protocols that were originally designed to support manually logging in to a SMTP server to send mail. Back before email was used as often as it is, that was a fairly common practice. When programs were designed to automate the task, they followed the same protocols. In order to change to a new system, every SMTP server and email program would have to be changed. This would be a much larger pain in the neck for the world at large than continuing to follow the standards as set forth in RFC 822, even if it dates to 1982.
For a while, it was an area of the world that only geeks used. Thus, they made the rules for their own convenience. Actually, they aren’t even rules. Most of the common protocols are set forth in RFC’s which are not official in any way.
The “rules” are simply a way of standardising things. And they were pretty much only used if they made sense at the time they were adopted. It would have been impossible in 1982 to ridicule non-geeks who didn’t follow the rules for SMTP, for example, because there weren’t any non-geeks that even knew what email was at the time.
Save your geek psychology explanations for when they are not contrary to the actual facts of the situation.
You misspelled both “ARPANet” and “the military.” You may want to look into a spellchecker.
Huh. So what was that thing I was surfing on an old Mac and on my Win3.1 machine back in 92/93?
Because if you make something case-insensitive, people will type it in lower-case because it’s easier.