The following image shows the Special Fields category expanded to show the special fields used in your report. The Report Date special field has been selected and is subsequently displayed on the Script Code sheet.
Special fields are designated by the tilde symbol (~) prefix and the brace symbols (that is, the { and } symbols, sometimes know as curly brackets) that enclose them, as shown in the example.
{~Report Date}
The fields Group Field Name and Group Field Alias are special cases. If there are no groups defined in the report, these fields return null.
If the script field is evaluated in a group section, these fields return the appropriate (current) group name or alias for the group; otherwise, when evaluated in a section that is not a group section, these fields return the group name or alias for the lowest-level group in the report, this being the last group processed.
For details about using special fields in your reports, see "Inserting a Special Field" under "Inserting Report Fields", in Chapter 4.