Monotonely Cauchy locally-solid topologies

The lattice of monotonely Cauchy (=pre-Lebesgue) locally solid topologies on a given lattice-ordered group is studied. Indentifying topologies agreeing on order bounded sets this lattice becomes a complete Boolean algebra isomorphic to the subalgebra of the lattice's complemented members and realizable as a Boolean algebra of order projections. Some consequences of these results are indicated.Work done while Tim Traynor was visiting professor at University of Napoli sponsored by CNR-Italia.