# Command Format > [HTML Version](commandformat.htm) All of the A-Shell/FAX commands start with "@@" which must appear in the first two columns of the line. As with the A-Shell GDI printing commands (which start with "//"), you may comment out a line by putting a semicolon in the third column. For example: @@;This is a comment and will not be printed. The basic format of all the commands consists of the @@ followed by a keyword. If the command takes any parameters, the keyword is followed immediately by an equal sign, followed by one or more comma-delimited parameters. For example: @@KEYWORD=param1\{,param2\}...\{,paramN\} The commands are not case sensitive, but there should be no space before or after the equal sign. Since the comma is the parameter delimiter, if a single parameter contains any embedded commas you must enclose the entire parameter in quotes (e.g. "Mr. Scholar, PhD"). All @@commands must appear before any blank or printable lines in the print file. (Scanning for @@commands stops when the first line which does not start with "@@" or "//" is encountered.)