In a bash shell (A), typing an ` (accent-grave) will start another shell prompt (B). The output of any command entered in B is a command for A. $ `> whoami`-bash: Joe: command not found(If my username were Joe.) $ man `> `What manual page do you want?Is there a man page for this, preferably with some examples? 
What does Linux accent-grave command do?
linux;bash
It is in the bash manual. Search for backquote (substitution)When  the  old-style  backquote form of substitution is used, backslashretains its literal meaning except when followed by $, `,  or  \.   Thefirst backquote not preceded by a backslash terminates the command substitution.  When using the $(command) form, all characters between  theparentheses make up the command; none are treated specially.Command substitutions may be nested.  To nest when using the backquotedform, escape the inner backquotes with backslashes.I find $() easier to use, especially when nesting things.