Special Tags

Special tags are tags that have special effects when they are attached to knowledge fragments. In order to distinguish from other normal tags, the name of the special tags start with '#'. For example, if you attach a #bookmark tag to a fragment, then the fragment will be added to the bookmark list on the sidebar.

#bookmark tag

#bookmark tag provides quick access to knowledge fragments. If a fragment is tagged with #bookmark, it will be shown in the bookmark list on the sidebar.
You can also bookmark a fragment by clicking on the bookmark button on the fragment toolbar.

#pre tag / #code tag

Adding a #pre tag to a text fragment displays the content "as is" and no further formatting will be applied to it (similar to HTML <pre>..</pre> mark-up).
Adding both #pre and #code tags to a text fragment displays the content "as is" with program-code syntax highlighting.
You can optionally specify the programming language in which the code is written with a #lang-<language name> tag, for more detail of language names, see the google-code-prettify document.

Program-code syntax highlighting

 * The HelloWorldApp class implements an application that
 * simply prints "Hello World!" to standard output.
class HelloWorldApp {
  public static void main(String[] args) {
    System.out.println("Hello World!"); // Display the string.

#trash tag

If you want to remove fragments that are no longer needed, attach a #trash tag to each of them. Fragments with #trash will be removed from the list/tree views but will not be deleted completely, so you can recover #trash fragments by removing the #trash tags from them.
You can do the same thing by clicking on the trash button on the fragment toolbar.
You can delete #trash-tagged fragments completely on the #trash tag page.

User Management - #user tag

The user management system is built into the piggydb's semantics seamlessly.
Piggydb has only one user ("owner") by default, but you can create other users just by creating fragments titled "username" and tagged with "#user" tag. These fragments are called "User Fragment", which can be created, changed, or deleted only by an owner.

Anonymous Access

Piggydb allows only authenticated (logged in) users to view, edit content by default. But the anonymous access feature has been available since version 4.4. You can enable anonymous access to let users view content without a login (anonymous users can only view content, but not register, edit or delete knowledge fragments).
To enable anonymous access, change the Piggydb settings "piggydb.enableAnonymous" value to "true".
If you use a War Package, you can download an anonymous-enabled package from here: http://sourceforge.net/projects/piggydb/files/ (file name: piggydb-<version>-anonymous.war).

#public tag

If you use Piggydb in private mode (Anonymous Access is off) and want to show some of your knowledge fragments to others without login, you can do this with #public tag. A fragment tagged with #public can be accessed via Document View (/document-view.htm?id=<n>) without login.
A fragment that is tagged with both #public and #home is called "Public Home" and it can be accessed at http://<your-piggydb-root>/public/. It is a good entry point for #public fragments.