Both programs add comment markers to scripts. Without the comment at the beginning, ARexx won't recognize a file as a script. In almost all ARexx macros you write, that should be the first line. It tells ARexx that it should retrieve information from the host program when a command is issued. The instruction sets up two-way communication between the host program and the macro.
Edge also adds the quotation marks to most of the command words.
This version of the macro uses a second of the special variables maintained by the interpreter, RC . An RC value of 0 usually indicates that the command was successfully executed. A value that is less than 10 is usually an informational warning, used for instance, to indicate that a search was successfully executed but did not find the specified word. A return value of 10 or greater indicates a more severe failure of the issued command.