The new useflag, "optimisememory" should be "optimizememory", with a "z" rather than "s".
spelling...unless optimise is technical term for something other than what I am thinking of: http://www.yourdictionary.com/ahd/o/o0102300.html
If I am wrong, then my deepest appologies.
Ok, I did a little bit of research. Optimise is the British spelling. Optimize is the American spelling. It does not really matter then.
Closing then. ;)