Today I Learned

Here's another reminder why expressive, namespaced ids are important. This time is about a label's for attribute.

<input id="phone">
<label for="phone"></label

This would work just as expected unless, for example, we have a svg sprite at the beginning of the document that includes an svg with a "phone" id.

<symbol id="phone" viewBox="0 0 61.4 48">...</symbol>
...
<input id="phone">
<label for="phone"></label

In this case, the label's for will match the first in a top-down order that has the target id.

And you will never know why clicking the label won't trigger the input.