Test requirements are definite in the Requirement Hierarchy in TestManager. The requirements hierarchy is a graphical outline of requirements and nested child requirements.
Requirements are stored in the requisite pro database. Requisite Pro is a tool that helps project teams control the development process by managing and tracking the changes of requirements.
TestManager haves a baseline version of Requisite Pro. The full version with more features and customizations is available in the Rational Suite TestStudio.