The Html editor is great, but often I want to copy and paste something into a case from a formatted document. When in the Html editor, the paste carries the formatting from the source document. It would be a nice feature to have a "Paste as plain text" button on the Html editor toolbar that would strip out formatting and paste only as plain text.
Today, I find I use the following work arounds:
Change to plain text editor mode just for the paste operation
Paste into notepad, than copy again and paste into Html editor.
I am using Kompozer and it has a right-click option to "Paste without formatting". Sometimes the option is greyed out but I think that if you are in "Preview" mode then you will have the option.