invo_context OpenVMS usage:invo_context_blk type: structure access: modify only mechanism: by reference Address of a valid invocation context block. The given invocation context block is updated to represent the context of the previous (calling) frame. The LIBICB$V_BOTTOM_OF_STACK flag of the invocation context block is set if the target frame represents the end of the invocation call chain or if stack corruption is detected.