A topological space is called submaximal if each of its dense
subsets is open and is called nodec if each of its nowhere dense subsets
is closed. Here, we study a variety of spaces some of which have already
been studied in C(X). Among them are, most importantly, quasi
P-spaces and pointwise quasi P-spaces. We obtain some new useful topological
characterizations of quasi P-spaces and pointwise quasi P-spaces.
Consequently, we obtain a close relation between these latter spaces and
submaximal and nodec spaces.