That was just a copypaste artifact I didn't bother to correct because it doesn't conflict with my convention anyway: all-uppercase BAREWORDS in my code are constants, except for the global filehandles predefined by Perl. (But I don't use bareword filehandles otherwise.)

There has even been an actual occasion where the compile-time inlining of constants tricked me, and in inocuous enough looking Perl no less. (It involved external code invoked by do to load configuration mixed with predeclarations — you can probably guess what happened.)