Iṭnāb (الإطناب) increases wording beyond the basic expression for a useful result. A general statement may be clarified, a distinguished member singled out, or a warning reinforced by repetition.
The source describes several techniques: clarification after initial generality (الإيضاح بعد الإبهام), tawshīʿ (التوشيع), specific after general (ذكر الخاص بعد العام), repetition, īghāl (الإيغال), tadhyīl (التذييل), protection against misunderstanding, completion and parenthesis.
The defining task is to identify the additional wording and its distinct benefit, rather than merely memorizing labels.