[ b ] :
Revised for security to be reliable and free of vulnerability holes.
Efficient, not to add any extra load/slowness to site.
Don’t collect private data.
Plugin adds “parent & hierarchy” functionality to posts (If you have problems, deactivate plugin and in “SETTINGS>PERMALINKS”, do “SAVE PERALINKS” 2 times).
See all available options and their description on plugin’s settings page.