symbol-name Specifies the symbol name that you want associated with a list of PCA commands. The symbol name can be up to 255 characters long and may include letters, digits, underscores, and dollar signs. It cannot start with a digit. If symbol-name is already defined, the new definition replaces the old definition. command-string Specifies the string of PCA commands to associate with the symbol name. The command string must be enclosed in quotation marks and consist of the first part of a PCA command, a whole command, or a list of commands separated by semicolons