SCO Visual Tcl commands are of the form:
Command [handle] [ -option [ optionArgs ...] ...]
Invocation of non-existent commands is handled using the normal Tcl command mechanism (the unknown(TCL) procedure). If it fails, the command generates a Tcl error.
Options for each command are validated by the command. When commands are sent to the server for execution, the interpreter validates the options and breaks the command-option-arguments string into a data structure for transfer to the server. The server performs fine-grained option validation and handling.