An exceedingly stupid act of paranoia; I knew the input _could not_ go above the normal ascii character set without errors elsewhere in the pipeline, it seemed

An exceedingly stupid act of paranoia; I knew the input _could not_ go above the normal ascii character set without errors elsewhere in the pipeline, it seemed therefore more robust to chose one that could by other invariants never be hit. That being said your group separators, had I thought harder about it might still have been a more valid answer. (but then I wouldn't be able to talk about it as quite so much of a dirty hack!) I imagine they aren't used much because frankly I hadn't even thought about their distinct function more than two to three times in my entire post-programming life.