A comment begins with a colon, semicolon, or ampersand. A line that begins with a comment delimiter is entirely a comment. Comments end at the end of a line.

: Comment
; Comment
& Comment

A comment can also follow a statement on a line. In this case an ampersand lets a partial statement continue on the next line.

Count += 1;                 Increment the count.

IF Count = Limit:           IF done counting,

DO while Count = 0         &DO while not started
      or Count > Limit     :      or past the end,

A block of lines can be commented out using begin and end block statements. A begin block statement has '<<' as the first characters on the line. They may be preceeded by spaces. All text after the delimiters is taken as a comment until the end block statment.

An end block statement has '>>' as the first characters on the line and may also have leading spaces. Any remaining text on the same line is also treated as a comment.

<<<<<<<< Begin a block comment.
Any lines inbetween are comments.
>>>>>>>> End of a block comment.

Note that all source code, including comments, can only contain printable characters. Tabs are also excluded.