Question: What does it mean in the helpful Do's & Don'ts "Don't Warranty the Mineral Title"

I am also very interested in this subject, since I have a lease in my hand, waiting for my signature. I had requested that the Warrant & Defend part be struck out, and also that they split the two, not contiguous properties onto separate leases. They refused to do either. I am at a point where I just sign it as is, or go find another landman that will work with me. If I refuse this lease, can they ‘force pool’ me, while I am looking for better offers?