Findings:

• Filesystem Hierarchy Standard
• Chomsky hierarchy
• Maslow's Hierarchy of Needs
• newsgroups hierarchies
• The Profanity Hierarchy of Severity
• Unix Filesystem Hierarchy
• The Digital Hierarchy
• Number Hierarchy
• Linux filesystem hierarchy
• generalization hierarchy
• anarchist hierarchy
• Confucian social hierarchy
• Wraith the Hierarchy
• animacy hierarchy
• Silverstein hierarchy
• cumulative hierarchy
• Catholic Church Hierarchy
• Kleene-Mostowski Arithmetical Hierarchy
• Analytic Hierarchy Process
• reconstructing the spiritual hierarchy with scientific mysticism
• root beer extract
• Yeast extract
• Goulard's extract
• Extracting pure caffeine from tea
• vanilla extract
• grape seed extract
• testicular extract theory
• Olive Leaf Extract
• cell-free extract
• extract
• pepper extract
• almond extract
• malt extract
• lemon extract
• chocolate extract
• Extracted bone demon
• Apple's Hierarchy of Skepticism
• hierarchy

If you Log in you could create a "Extract Hierarchy" node. If you don't already have an account, you can register here.