Word polygon each word. Further rules may be set. One letter may be highlighted, and all words made must include that letter. A minimum length for words may be set. There is always at least one word that can be made using all of the available letters, and the rules may require that a maximum length word be found. With each puzzle, a number of words to aim for is usually included as a guide, with three difficulty ratings: good, very good and excellent. Each puzzle differs in its target, depending on the letters given to work with. In Australia, "The Advertiser"
Letter frequency word variants when counting, such as "abstracts", "abstracted" and "abstracting" and not just the root word of "abstract". This system results in letters like "s" appearing much more frequently, such as when counting letters from lists of the most used English words on the Internet. A final variant is to count letters based on their frequency of use in actual texts, resulting in certain letter combinations like "th" becoming more common due to the frequent use of common words like "the". Absolute usage frequency measures like this are used when creating keyboard layouts or letter frequencies in old fashioned printing