Normally when you copy text in Firefox it retains the original formatting when you paste it elsewhere (such as into
Word or into a blog post). This is not always desired.
The workaround to lose the formatting that I used to use involved opening Notepad, pasting the text into there, copying from Notepad (Notepad is only capable of using plain text), and then pasting to whatever my destination was in the first place. This add-on puts additional choices such as “Copy as Plain Text” to the right-click context menu to make it as easy to copy text without formatting as it is to copy the text with the formatting.