> 54-XX General topology

54-00 General reference works (handbooks, dictionaries, bibliographies, etc.)	54-01 Instructional exposition (textbooks, tutorial papers, etc.)	54-02 Research exposition (monographs, survey articles)
54-03 Historical (must also be assigned at least one classification number from Section 01)	54-04 Explicit machine computation and programs (not the theory of computation or programming)	54-06 Proceedings, conferences, collections, etc.
54-99 General topology (not classified at a more specific level)	54AXX Generalities	54BXX Basic constructions
54CXX Maps and general types of spaces defined by maps	54DXX Fairly general properties	54EXX Spaces with richer structures
54FXX Special properties	54GXX Peculiar spaces	54HXX Connections with other structures, applications
54J05 Nonstandard topology

54-XX General topology