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The ‘merge’ command requires three parameters. Parameter one and/or two can be plain text or the names of existing variables. If the text contains spaces then the text must be enclosed by delimiters. If either one of the first two parameters are names of variables that have yet to be defined, the command will fail and script processing will terminate. The third parameter MUST be a variable. This variable can be a new one, or the name of an existing variable. If it is an existing variable, it’s contents will be overwritten by the new value.