Word description
This symbol is passed as the abi argument to alien-indirect, alien-callback, alien-assembly, and add-library to indicate that Microsoft Visual C++ calling convention should be used, where the first argument (which must be a "this" pointer) is passed in a register and the function cleans up its own stack frame before returning to the caller. This symbol only has meaning on 32-bit x86 platforms.

See also
cdecl, stdcall, fastcall