> Historically, BSS (from Block Started by Symbol) is a pseudo-operation in
UA-SAP (United Aircraft Symbolic Assembly Program), the assembler developed in
the mid-1950s for the IBM 704 by Roy Nutt, Walter Ramshaw, and others at United
Aircraft Corporation. The BSS keyword was later incorporated into FORTRAN
Assembly Program (FAP) and Macro Assembly Program (MAP), IBM's standard
assemblers for its 709 and 7090/94 computers. It defined a label (i.e. symbol)
and reserved a block of uninitialized space for a given number of words. In this
situation BSS served as a shorthand in place of individually reserving a number
of separate smaller data locations. Some assemblers support a complementary or
alternative directive BES, for Block Ended by Symbol, where the specified symbol
corresponds to the end of the reserved block.