How I Got Firefox To Accept The TEL Tag
And Place Phone Calls From Web Pages
Published in 2600 Magazine, 2011 Autumn, Volume 28:3

by The Cheshire Catalyst

Those that know me know that I've railed against Flash® for many years as a bandwidth hog that is, in most cases, mere "eye candy" with very little "information content". As a result, I've gotten together with a friend to form PHonePHriendly.Com to write simple web pages for mobile phone web browsers. We wrote a page with the conference schedule of The Next HOPE last July.

Conference schedules are exactly the kind of information you want immediately, with "just the facts, m'am". When you look at the site at http://H.PH2.Mobi you'll notice that the numbered menu items can be chosen on most mobile phones by simply hitting the number on your phone's dial-pad which will choose the menu item. Since menu choices 1, 2, and 3 are the schedules for Friday, Saturday and Sunday respectively, these menu choices can be chosen when you are on any of the pages on the site. Hit 1 for Friday, and from the Friday page, you can hit 2 for Saturday to jump there immediately.

Each date has it's own directory, and the directory name is the date of that day. This way, the web address becomes another Clue for the user as to what date we're talking about. Using the day of the week would have the directory names scattered as they sorted alphabetically (alphabetic order would be Friday, Monday, Saturday, Sunday, Thursday, Tuesday, Wednesday). Using the date format MM-DD (example: 01-31) directory names sort logically.

Once you're on the page for the day you want to view, you see times of the seminars. The problem on a mobile phone web browser (if it isn't a graphic oriented "smart phone" with touch-screen), is you have to scroll down a web page using a "5 way-navigator". By having a menu at the top of the page, you can quickly maneuver to the time of the conference seminar you're about to attend, then press "Select" (the center button in the navigator), and it will jump you to the time of day you're interested in on that same page. Then choose the seminar you want at that time of day and you will be taken to a web page for that day and time, dropping you at the information on the session you want to attend within that hour by using the NAME tag for the room that session is in. The users get directly to the information they want. There is no reason to do an "app" that only iPhones or Android phones can access. Make a simple web page, and any web browser on any device can read it.

So it's possible to make web pages that would be useful on mobile phones. That's great, but it's a phone! What if you want to visit a web page, and call the phone number that's there?

Anyone who'se written web pages is familiar with the "mailto" tag, which looks like <a href=" message" target="_blank">E-Mail Me</a> (if you didn't know about the "subject" thing, I'll bet you start using it). The "mailto" tag is standard HTML (Hyper Text Markup Language), and works with any browser. Even most phones will jump you to a Message or E-mail App on the phone to send e-mails. The trick is to get computers to use a Tag that's common to modern moble phones, but not to most computer desktop browsers, the Tel tag.

The Tel tag looks alot like a Mailto tag, <a href="tel:+1 311 555-2368">Call Me</a>. The thing is, most desktop browsers haven't got a clue as to how to use the Tel tag. Here's how I got Firefox to accept it.

First, I installed Skype on my computer. This VoIP (Voice Over Internet Protocol) application is the "Gold Standard" for computer to computer voice communications, and (if you're willing to pay for it) place calls to POTS (Plain Old Telephone Service) phones on the PSTN (Public Switched Telephone Network). Skype conforms to all International Standards called "Reccommendations" (the International Telecommunications Union can't force soverign nations to conform to standards, but can make "Reccommendations"). Skype does that because it's based in Europe, where you're crossing someone elses international border every 50 miles or so (at least, that's how it seems).

When you install Skype, it inserts code into the file "mimeTypes.rdf" in the directory "C:\Program Files\FirefoxPortable\Data\profile". I use Firefox Portable on my desktop, because it doesn't interact with the Microsoft Registry. Normally it runs off a Thumb Drive so you can carry your Bookmarks with you to use on any computer you need to borrow when you need to access websites.

What I did was search for the word "skype" (without quote marks, of course) within "mimeTypes.rdf" using Notepad, a program that is a simple ASCII (American Standard Code for Information Interchange) editor. Each time I found the word, I copied the line or lines needed, pasted a copy of the line(s) below the existing one(s), and replaced the word "skype" in the copied line with the word "tel" (there's more than one of these line groups to deal with). You don't have to put in the ": " colon character that's needed if you use the Tag in a web page. If you look for the word "mailto" in the same file, you'll see that no colon character is used for that keyword in this file. Some of the things to copy have mutiple lines. One such starts with "<RDF:Description ...", has a few lines of code, and end in "</RDF:Description>" You need to copy these whole sections, changing only "skype" to "tel". Just see what's in the file for "skype" and make similar text with "tel".

Once edited, I saved the file, closed Firefox, and brought Firefox up again so it read the new version of the file as it reloaded. Then I went to my mobile web page. http://CheshireCatalyst.Com/m and chose Menu Choice 6 for the US Naval Observatory Master Clock where Durward Kirby, the announcer from The Gary Moore Show in the 1960's, is immortalized as the Navy's talking clock at 202-762-1401. I don't pay for Skype's POTS connection services, but clicking the hyperlink on the page brings up Skype, so I know the Tel tag there works.

Before you put Skype on your computer, you couldn't handle telephone calls on your computer. With Skype, you still couldn't handle the Tel tags that simple mobile phone browsers could handle. Hopefully Skype will figure it out in a future upgrade, but after this simple file edit, your computer can handle things your computer should handle when it comes to voice calls and the Internet.

The Cheshire Catalyst (Richard Cheshire) is a former editor of the TAP Newsletter of the 1970's & 80's. Besides writing web pages for mobile phone web browsers, he also helps 2600 put on the biennial HOPE Conferences.


I tried experimenting with a "Skype" tag, and guess what? It works!

A link such as <a href="skype:cheshire2600">Skype Me</a> will bring up Skype, and set up a call to my Skype account. Of course, I may not be online at the time, but send me a message.


The newest versions of Skype now use their "add-on" to your browser to allow the TEL tag to feed the hyperlink from your browser to Skype. I like to think I started that snowball down the hill.

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2600 Magazine: The Hacker Quarterly - Autumn 2011