REGISTER(1)                 General Commands Manual                REGISTER(1)

NNAAMMEE
       register - conditional testing whether a register is defined

DDEESSCCRRIIPPTTIIOONN
       not yet defined
       now defined

       identifier + identifier:      myreg is defined

       escape sequence after identifier: -myreg is defined

OpenBSD                        February 6, 2019                    REGISTER(1)