1. **State the problem:** Calculate the value of $-17 - (-6)$. 2. **Recall the rule:** Subtracting a negative number is the same as adding its positive counterpart. So, $a - (-b) = a + b$. 3. **Apply the rule:** Replace $-(-6)$ with $+6$, so the expression becomes $-17 + 6$. 4. **Perform the addition:** $-17 + 6 = -11$. 5. **Final answer:** $-17 - (-6) = -11$.