diff --git a/phosphor-regulators/docs/config_file/compare_vpd.md b/phosphor-regulators/docs/config_file/compare_vpd.md
index e87ef87..1c2b924 100644
--- a/phosphor-regulators/docs/config_file/compare_vpd.md
+++ b/phosphor-regulators/docs/config_file/compare_vpd.md
@@ -3,12 +3,20 @@
 ## Description
 Compares a VPD (Vital Product Data) keyword value to an expected value.
 
-The following keywords are currently supported:
+VPD is information that describes a hardware component.  VPD is typically read
+from an EEPROM on a Field-Replaceable Unit (FRU).  For this reason, VPD is also
+called "FRU data".
+
+The following VPD keywords are currently supported:
 * CCIN
 * Manufacturer
 * Model
 * PartNumber
 
+This action can be used in an [if](if.md) condition to execute actions based on
+a VPD keyword value.  For example, you could set the output voltage only for
+regulators with a specific Model number.
+
 ## Properties
 | Name | Required | Type | Description |
 | :--- | :------: | :--- | :---------- |