54Dxx Fairly general properties

• 54D05 Connected and locally connected spaces (general aspects)
• 54D10 Lower separation axioms, ($T_0$--$T_3$, etc.)
• 54D15 Higher separation axioms (completely regular, normal, perfectly or collectionwise normal, etc.)
• 54D20 Noncompact covering properties (paracompact, Lindelof, etc.)
• 54D25 ``$P$-minimal'' and ``$P$-closed'' spaces
• 54D30 Compactness
• 54D35 Extensions of spaces (compactifications, supercompactifications, completions, etc.)
• 54D40 Remainders
• 54D45 Local compactness, $sigma$-compactness
• 54D50 $k$-spaces
• 54D55 Sequential spaces
• 54D60 Realcompactness and realcompactification
• 54D65 Separability
• 54D70 Base properties
• 54D80 Special constructions of spaces (spaces of ultrafilters, etc.)
• 54D99 None of the above but in this section