The cat command is rather infamous for using -v to mean “visual” (as in, convert invisible characters to something visible). But the infamy is not that it used

The cat command is rather infamous for using -v to mean “visual” (as in, convert invisible characters to something visible). But the infamy is not that it used -v for something other than “version”—I doubt that convention existed in 1983, when the complaint was made—but rather that it was a sign of the ever‐growing complexity of specific Unix tools at the expense of the harmony of the whole system. See “Program design in the UNIX environment,” by Rob Pike and Brian Kernighan, USENIX 1983: http://harmful.cat-v.org/cat-v/ http://harmful.cat-v.org/cat-v/