These are control statements which pass information to the script interpreter before the script is executed.
The RISC OS convention is to use the 'eggy' character '¤', however this is not so easy to do on a Windows computer, so the Windows script interpreter will also accept lines beginning '@'.
Under Windows, you can obtain the '¤' by holding down the Alt key while you tap out 0 1 6 4 on the numeric keypad.
¤script...
The only currently defined control statement is:
¤script "<description string>"
This passes a description to the script interpreter which is then made available - by description - in the script menu.
The picture on the right shows how this works. The "!startup" script has no description embedded, so it is listed by its filename (extension omitted), while the other scripts have descriptions and, hence, they are listed according to what they do. Up to twenty scripts can be listed in the menu.
Specifics
You cannot use the '@' form under RISC OS.
Script descriptions are only partially utilised under RISC OS; the menu lists scripts by filename.