A package body is created in the SQL-window of TOAD, The package body sometimes contains an '&' sign as a part of a string.
For example :
l_report := '&report=reportname';
The '&' sign is followed by something, but as a part of a string.
When the package body is compiled, TOAD asks to give a value for the script variable report. But '&report' is not a script variable, because it is a part of a string.