[html] href="tel:" and mobile numbers

If I use tel: I should write the international phone code, like that.

<a href="tel:+6494461709">61709</a>

So far, so good, but I can't find information on how to write a cell phone number in an "international" way, if there is one.

It's the same. Your international format is already correct, and is recommended for use in all cases, where possible.

I know the OP is asking about international country codes but for North America, you could use the following:

<a href="tel:+1-847-555-5555">1-847-555-5555</a>

<a href="tel:+18475555555">Click Here To Call Support 1-847-555-5555</a>

This might help you.

As an additional note, you may also add markup language for pausing or waiting, I learned this from the iPhone iOS which allows numbers to be stored with extension numbers in the same line. A semi-colon establishes a wait, which will show as a next step upon calling the number. This helps to simplify the workflow of calling numbers with extensions in their board. You press the button shown on the bottom left of the iPhone screen when prompted, and the iPhone will dial it automatically.

<a href="tel:+50225079227;1">Call Now</a>

The pause is entered with a comma ",", allowing a short pause of time for each comma. Once the time has passed, the number after the comma will be dialed automatically

<a href="tel:+50225079227,1">Call Now, you will be automaticlaly transferred</a>

The BlackBerry browser and Safari for iOS (iPhone/iPod/iPad) automatically detect phone numbers and email addresses and convert them to links. If you don’t want this feature, you should use the following meta tags.

For Safari:

<meta name="format-detection" content="telephone=no">

For BlackBerry:

<meta http-equiv="x-rim-auto-match" content="none">

Source: mobilexweb.com