The tiddlers within registered plugins behave as ShadowTiddlers: they can be freely overwritten by creating a tiddler with the same title, but deleting that tiddler restores the underlying tiddler value from the plugin.
Plugins have a
plugin-type field that may take the following values:
plugin(default) - a plain plugin
theme- a theme plugin (see ThemeMechanism)
language- for translations only
Plugins conventionally have a title of the form
$:/plugins/publisher/name. Plugins that are part of the core TiddlyWiki distribution have titles of the form