It is considered a requirement by some search engines.
Word Press provides a couple of functions to validate only some types of data.
When creating Word Press plugins and themes, which will be used across thousands of websites, you need to be cautious about how to handle both the data coming into Word Press, and the data that is being presented to the user.
In this tutorial, we are going to look at the native functions that can secure, clean and check data that is coming in or going out of Word Press.
This is done to prevent email CSS from overwriting Gmail styles.
Word Press Example: Widget titles cannot have HTML tags in them.