How do you understand that a requirement is correctly specified?

A correctly described requirement should be:

• Unambiguous — does not allow different interpretations.
• Complete — covers all necessary aspects without omissions.
• Verifiable — can be checked whether the requirement has been met.
• Realistic — achievable considering resources and constraints.
• Specific — without vague formulations.

For example, instead of "The system should process requests quickly," it is better to write "The system should process 1000 requests per second with a delay of no more than 200 ms."

Techniques often used to verify requirements include:

• Review involving interested parties.
• Creating test cases based on requirements.
• Prototyping or modeling.

If a requirement passes these checks, it can be considered correctly described.