Rubric refers to the written instructions for a task.

Example
The writing part of a proficiency exam such as FCE or IELTS has a rubric giving instructions.

In the classroom
Learners may need to be trained to pay attention to the rubric, especially for an exam. They can be encouraged to do this by group analysis of questions, the highlighting of key points, and quick answer plans - which they can then explain to other learners.