Mythryl supports shell-style comments opened by a # character and extending to the end of the line. These are by far the most commonly used for of comment in Mythryl.
Unlike in many scripting languages, in Mythryl in order to open a comment the opening hash character must be followed by whitespace, a second hash character, or an exclamation point, The latter to support shebang script invocation via a #!/usr/bin/mythryl line at the top of a script:
this is code; # This is a comment.
this is code; ## This is a comment.
this is code; #! This is a comment.