5.5.4 Symbol Attributes for COFF
The COFF format supports a multitude of auxiliary symbol attributes;
like the primary symbol attributes, they are set between .def and
.endef directives.
5.5.4.1 Primary Attributes
The symbol name is set with .def; the value and type,
respectively, with .val and .type.
5.5.4.2 Auxiliary Attributes
The as directives .dim, .line, .scl,
.size, .tag, and .weak can generate auxiliary symbol
table information for COFF.