An equal sign is often used for the eyes in place of the colon, without changing the meaning of the emoticon. In these instances, the hyphen is almost always either omitted or, occasionally, replaced with an 'o' as in =O) . In most circles it has become acceptable to omit the hyphen, whether a colon or an equal sign is used for the eyes, e.g. :) . In some areas of usage, people prefer the larger, more traditional emoticon :-) . In general, similar-looking characters are commonly substituted for one another: for instance, o, O, and 0 can all be used interchangeably, sometimes for subtly different effect. In some cases, one type of character may look better in a certain font and therefore be preferred over another.