Each line contains either a single character symbol marker , or a field name with selection values. And Trees' and 'Or Trees', with another symbol used to denote a 'Simple And' connection. First occurrence indicates that the next line contains Index Value field names. And Tree is the most simple subtree of the index dictionary. Field Name lines are discussed below.
Tree is a bit more complex.
Or Tree' symbol is followed by any number of Field Name lines. In other words, use of the 'Simple And' implements a different precedence. A Field Name Line consists of a single field name followed by two values. These values are referred to as Val1 and Val2. Note that underscores should be used in place of blanks within all fields that have embedded blanks in their names.