Topics to be covered:

1. The frame S_c(L) of joins of closed sublocales of a locale L; motivation (scatteredness).
2. The relation of S_c(L) to the coframe of sublocales S(L).
3. S_c(L) as a "discrete cover" of L, modelling discontinuity.
4. Comparing S_c(L) with the frame of sublocales S(L)^op. Advantages, but also a disadvantage.
5. The problem of characterization of S(L) among general coframes, why it would be nice to know more about it.