In reply to fazza
Parameters are user defined with a name (any name you want with no spaces or odd characters) that is usually used to define some type of simple info about the model being created. This information can be entered as the value for the named parameter. See example reply for sh_luoyx. This information stays with the model as a element of it which can be used in many ways later on in the design process parametrically. Most Companies have a standard set of these parameters that they expect to see with chosen names that users simply enter the values for when creating designs. Pro/E has a fe built in set of parameters, that is imbeded with the software for each object like scale, date, filename, etc, which can also be shown on the drawing eliminating the need to enter this data everytime you create a drawing by automatically entering it into the title-block and to keep everything consistent.
You create the parameters using Pro/E menu functionality, see the pro/e help file for more info on how to do this. This functionality applies not only to Pro/E 2001 but all Pro/E versions in use today.