What you are seeing is the Markdown Editor that comes with v11. You can Customize the DocType and change the Text Editor to HTML Editor and that will let you insert raw HTML. (Note: this does not give you an actual HTML Editor, just an empty text field that will accept HTML and a Preview window that will give you an approximation of the web view.
Step-by-Step (if you are a newbie like me)
- Go to the Letterhead you want to update.
- Under the Menu dropdown there is choice to “Customize”. This brings up the DocType.
- Scroll down to the “Fields” section. In my v11 version Line 4 is Content and Line 5 is Footer (your Doctype might be different.)
- Both of these lines have a “Type” of “Text Editor”. If you click and hold on that for a second, you will se a long list of other types displayed.
- Select “HTML Editor” and then click “Save”. When you return to the Letterhead you should see an empty text field that will take your raw HTML.
Note: You can use this same process on other DocTypes and Fields. If you have Web Pages that require an actual HTML Editor you might want to look at this link.