[Update: It seems I interchanged “em” and “de” throughout this post. ]
Up to this point, I’ve been labeling printed parts with emdebossed legends that look OK on the solid model:
Alas, the recessed letters become lost in their perimeter threads:
Raising the legend above the surface (“deembossing”) works reasonably well, but raised letters would interfere with sliding the battery into the holder and tend to get lost amid the surface infill pattern.
The blindingly obvious solution, after far too long, raises the letters above a frame embossed into the surface:
Which looks OK in the real world, too:
The frame is one thread deep and the legend is one thread tall, putting the letters flush with the surrounding surface and allowing the battery to slide smoothly.
The legend on the bottom surface shows even more improvement:
An OpenSCAD program can’t get the size of a rendered text string, so the fixed-size frame must surround the largest possible text, which isn’t much of a problem for my simple needs.
The Smell of Molten Projects in the Morning 
The Internet seems to think that what you’re doing now is embossing and what you were doing before is debossing. :-)
Either way, someone is wrong on the Internet!
Apparently, after careful consideration and research, I completely screwed up.
Thanks for the nudge …