Every [JSup Tag type|tag type] has its own '''default initial value''': * [JSup boolean tags|Boolean]: false. * [JSup numeric tags|Numeric]: 0. * [JSup string tags|Variable length string]: an empty string * [JSup string tags|Fixed length string]: a string of requested length filled with spaces (or other ''pad character'' defined by the [JSup Tag classes|tag class]. * [JSup Object tags|Object]: null (an [JSup Object tags|object tag] cannot have custom initial value). A '''custom initial value''' of a tag can by provided by the [JSup Tag classes|tag class] the [JSup tag|tag] belongs to or by using the initialValue [JSup Using tag properties|tag property].