Related tasks
Create a BookVars file based on the variables in an existing Frame file
Set up a more complex BookVars file (two groups, three variable definitions each)
Set up a shared group that is included in two other groups
Reference a common BookVars file
Delete specific variables from all files in a book
Rename specific variables in all files in a book
Replace specific variables in all files in a book
Related information
Using Special Characters

Set up a simple BookVars file (one group, three variable definitions)

When you run the Import Variables command with this BookVars file, all of the files in the book will be updated with the three variables, PRODNAME, PRODURL, and PRODEXE. If these variables already exist, their definitions will be updated, if they don't exist, the variables and definitions will be added to each file. Because there is just one group defined, you won't be prompted to select a group. 
[General] 
UpdateMarkerVars=0 
AltBookVarsFile= 
DeleteVarCode= 
RenameVarChar= 
ReplaceVarChar= 
UpdateMarkerVars=0 
EditorType=0 
 
[Groups] 
Count=1 
1=MainGroup 
 
[MainGroup] 
;VARIABLE=DEFINITION 
PRODNAME=My Cool Application 
PRODURL=http://www.mycoolapp.com 
PRODEXE=mycoolapp.exe