Every [JSup Tag type|tag type] has its own '''default initial value''':
 * [JSup boolean tags|Boolean]: <TT>false</TT>.
 * [JSup numeric tags|Numeric]: <TT>0</TT>.
 * [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]: <TT>null</TT> (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 <TT>initialValue</TT> [JSup Using tag properties|tag property].