The "Fields" command starts the list of the fields of the table associated with some rule. It has no parameters.

Syntax:
Fields

Example:

Fields
 Field Name="CustomerTypeID"
  DataType Code="-8" Name="nchar" length="10"
  Pattern="$Unique($RString(1,10,5,0,0))"
 Field Name="CustomerDesc"
  DataType Code="-10" Name="ntext"
  Pattern="$IfR(10,\NULL,$RString(1,4096,5,0,0))"