DataSet-related information that is valid for the whole session is called metadata.
You can store this type of information for each DataSet or DataGroup separately, or you can predefine a set of default meta-variables, including possible value lists.
(Previously called Independent Variables)
Using predefined meta-variables and meta-values to collect your metadata is of course the more comfortable way of handling this type of information. Defining meta-value lists helps you to get consistent information and ensures proper value entries.
Predefine Meta-Variables
Because default meta-variables are document-specific items, they are located in the File properties dialog.
▪Click Insert - Metadata - Define 
.
The middle part of this dialog, allows you to define variables to store Metadata, including value lists to choose from:
This is a free text field, in which you type the names for your variables, followed by an = and the possible values it can contain:
▪Enter the name of your variable.
▪Enter the equal sign (=) after the variable.
▪Possible values need to be separated by a comma (,).
Values should not contain spaces.
Only one of the predefined values can be selected.
▪If the value requires individual entries, enter a question mark (?) instead of the values.