Spelling
Everytime you look up a word in the dictionary, remember that it is necessary for you to learn how to spell it. This dictionary follows fowler in this as in various other matters. Verbs ending with -ize and nouns with -ization can be, and in England popularily are, spelt with an s in place of z which is preffered by scholars and in the States. You may have your own preference, but it is wise to stick to the form you have chosen.