<input list="ppk" name="list" />
<datalist id="ppk">
	<option label="ppk" value="ppk"></option>
	<option label="JavaScript" value="JavaScript"></option>
</datalist>

• The Chromia offer a dropdown under an arrow, and match the predefined values from start; i.e. entering a 'p' only shows option 'ppk' since that starts with a p.
• IE does the same, except that the dropdown automatically opens when you focus on the field.
• Firefox doesn’t show anything initially, but substring-matches whatever you fill in; i.e. entering a 'p' shows both options since both contain a p.

• The Chromia support all except datetime.
• On Mac, the Chromia always show US-formatted dates and times. As far as I know there’s no way to change that. Windows listens to the user preferences and switches time and date formats accordingly.
• Using the input itself is annoying, but the Chromia also offer some good popup date pickers for everything but time.

The most annoying one is time, which requires an am/pm input. Entering 14:33 is not possible. However, the server receives a 24hrs-formatted time anyway.

With dates the server received yyyy-mm-dd; with weeks yyyy-Www (where the W is an actual 'W').

• IE10 and 11 remove the value onblur if it’s not a number. This is a useful bit of interface other browsers should copy.

Mac browsers except Firefox give the field rounded corners, but that’s the full extent of the support for this type. To be fair, I don’t know what else they’re supposed to be doing.

<input type="text" autofocus>

The browser automatically focuses on this field when the page is loading.

<input type="file" multiple>

Allows users to upload multiple files at once.

<input pattern="[0-9]{4}[ ]?[A-Z]{2}" />

The value must conform to the regexp pattern, or submission is halted.

The error message contains the element’s title, if any.

<input type="text" placeholder="Some text">

The placeholder text is shown as long as the field is unfocused and the user has not entered another value.

<input type="number" readonly>

User cannot enter a value in the form field.

<input type="text" required>

Form submission is halted if a required field does not have a value.

• Safari doesn’t send a wrong value to the server, but doesn’t alert the user that something is wrong, either. Pressing on the arrows brings you back to the expected 3-6-9-12 range.

If you set step="3" and enter 11 in the field and submits the form, the following happens:

• IE tells the user to enter a valid value but doesn’t tell the user what a valid value looks like.
• Safari removes the value and sends the rest to the server. This is BAD since the user has no clue that his submission has gone wrong.
• Firefox and the Chrome-based browsers show an error message with the closest legal values.