Hobbit,
You have misunderstood the question. For some one instructing and only instructing there are no duty limits or flight time limits.
But if you are working for an AOC holder and instruct on the side then the instructional hours need to be accounted for within the limits slr stated.
So SLR each instructional hour you do on the side would in theory count towards your 100 monthly and 1000 hour total. Some operators may not allow you to instruct on the side because of this.