Ever notice how some common Blender words that we use on a regular basis, e.g. viewport, SHFT, CTRL, and wireframe, always throw a spelling exception? Is there any way to get these, and other common Blender terms added to the Blender.stackexchange spell check dictionary? And if there is a way to do this, what other words should be added?
As gandalf3 said in the comments, the site has no control over the spell checking, that is handled completely by the browsers.
However you can add the trouble words to your own browser's dictionary.
Words such as: shader, compositing, outliner and viewport are already in my browsers dictionary.