diff --git a/R/read_habitatdata.R b/R/read_habitatdata.R
index 591300d2..6ba3acac 100644
--- a/R/read_habitatdata.R
+++ b/R/read_habitatdata.R
@@ -90,8 +90,12 @@
 #'     \item \code{phab}: proportion of polygon covered by type, as a percentage.
 #'      \code{FALSE} when vegetation type is uncertain.
 #'     }
+#'     Since version \code{habitatmap_stdized_2020_v1}, rows are unique only
+#'     by the combination of the \code{polygon_id}, \code{type} and
+#'     \code{certain} columns.
 #'     }
 #'
+#'
 #' @family functions involved in processing the 'habitatmap' data source
 #'
 #' @references
@@ -985,6 +989,9 @@ read_habitatmap <-
 #'     \item \code{source}: states where \code{type} comes from: either
 #'     \code{habitatmap_stdized} or \code{habitatmap_stdized + interpretation}
 #'     }
+#'     Since version \code{habitatmap_terr_2020_v1}, rows are unique only
+#'     by the combination of the \code{polygon_id}, \code{type} and
+#'     \code{certain} columns.
 #'     }
 #'
 #' @family functions involved in processing the 'habitatmap' data source
diff --git a/man/read_habitatmap_stdized.Rd b/man/read_habitatmap_stdized.Rd
index 9349ccae..f8b4a867 100644
--- a/man/read_habitatmap_stdized.Rd
+++ b/man/read_habitatmap_stdized.Rd
@@ -42,6 +42,9 @@ A list of two objects:
     \item \code{phab}: proportion of polygon covered by type, as a percentage.
      \code{FALSE} when vegetation type is uncertain.
     }
+    Since version \code{habitatmap_stdized_2020_v1}, rows are unique only
+    by the combination of the \code{polygon_id}, \code{type} and
+    \code{certain} columns.
     }
 }
 \description{
diff --git a/man/read_habitatmap_terr.Rd b/man/read_habitatmap_terr.Rd
index ac84cb35..d981a7b8 100644
--- a/man/read_habitatmap_terr.Rd
+++ b/man/read_habitatmap_terr.Rd
@@ -72,6 +72,9 @@ A list of two objects:
     \item \code{source}: states where \code{type} comes from: either
     \code{habitatmap_stdized} or \code{habitatmap_stdized + interpretation}
     }
+    Since version \code{habitatmap_terr_2020_v1}, rows are unique only
+    by the combination of the \code{polygon_id}, \code{type} and
+    \code{certain} columns.
     }
 }
 \description{