1.4.1 Switches The following switches allow the user to control how Regina executes the supplied Rexx program. Switches are recognised by a leading hyphen character; `-’, followed immediately by a single alphabetic character. Some switches allow for optional parameters. These, too must follow the switch without any intervening spaces. All switches and their optional parameters are case-sensitive. -t[trace parameter]Turn on the specified tracing level. The optional trace parameter indicates the tracing level to be used. See the TRACE command later in this document for an explanation of each trace level.