Reference: Assign
While/End_While
A variable name is a string of characters that does not include blanks or special characters. It is used to identify a string, numeric, or logical value. Variables are assigned values using the Assign command or the While command, and are referenced in a script with the escape sequence %’<variable>’. Beyond FTP provides a number of predefined variables that provide access to certain operational script values. A special naming convention is used to distinguish variables being assigned within an Each_Server context. See the Assign command.
The variable assigned in the While command has the further restriction that it is valid only within the scope of that While statement. It allows you to iterate through a list of files, and contains the current file name for this iteration. The path is not included with the name.