A recent LWN.net article <https://lwn.net/Articles/947941/> (paywalled for a while) pointed at https://bugs.debian.org/1041731 and the topic of "-" vs "\-".
Given the following input: -\-\[u002D]\[u2013]\[u2014]+\[u2212] Feeding it through `groff -Tutf8`, I get ‐−-–—+− <U+2010><U+2212><U+002D><U+2013><U+002B><U+2014> groff_char(7) says \- maps to "minus sign/Unix dash". Ambiguous, but ok, it is what it is. Is there a better way though than to explicitly use \[u002D] to get a guaranteed U+002D? Second, I turn to PostScript output that is generated by `groff -Tps`. One observes: troff:<standard input>:1: warning: special character 'u002D' not defined (Converting the PS to PDF and opening that with evince), the rendered view shows a hyphen, a minus, an endash, an emdash, and another minus but rendered in a different vertical position which does not line up with the '+' sign. Third, when one copy-pastes the string shown in evince, I get back: -−–—+− <U+002D><U+2212><U+2013><U+2014><U+002B><U+2212> I expected to receive: <U+2010><U+002D><U+2013><U+2014><U+002B><U+2212> so that copypasting commands from PS/PDF would work "right" similarly as it does for manpages when they use \-.