diff --git a/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastDayNotice.java b/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastDayNotice.java
index 9e5d08d768..9108ccb5bf 100644
--- a/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastDayNotice.java
+++ b/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastDayNotice.java
@@ -3,7 +3,8 @@
 import org.mobilitydata.gtfsvalidator.annotation.GtfsValidationNotice;
 
 /**
- * The `prior_notice_last_day` value is required for prior day `booking_type` in booking_rules.txt.
+ * The `prior_notice_last_day` is required when booking_type=2 (prior day booking) is specified in
+ * booking_rules.txt.
  */
 @GtfsValidationNotice(severity = SeverityLevel.ERROR)
 public class MissingPriorNoticeLastDayNotice extends ValidationNotice {
diff --git a/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastTimeNotice.java b/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastTimeNotice.java
index cb37140339..5420fd9798 100644
--- a/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastTimeNotice.java
+++ b/core/src/main/java/org/mobilitydata/gtfsvalidator/notice/MissingPriorNoticeLastTimeNotice.java
@@ -3,7 +3,8 @@
 import org.mobilitydata.gtfsvalidator.annotation.GtfsValidationNotice;
 
 /**
- * The `prior_notice_last_time` value is required for prior day `booking_type` in booking_rules.txt.
+ * The `prior_notice_last_time` is required when booking_type=2 (prior day booking) is specified in
+ * booking_rules.txt.
  */
 @GtfsValidationNotice(severity = SeverityLevel.ERROR)
 public class MissingPriorNoticeLastTimeNotice extends ValidationNotice {