diff --git a/R/pkg-versions.R b/R/pkg-versions.R
index ddb2420..04ea8a2 100644
--- a/R/pkg-versions.R
+++ b/R/pkg-versions.R
@@ -1,3 +1,6 @@
+# Functions to extract version numbers of packages, both from CRAN and latest
+# GitHub releases.
+
 check_pkg_version_path <- function () {
     cm_path <- normalizePath (file.path ("raw_cm.json"), mustWork = FALSE)
 
@@ -13,7 +16,13 @@ check_pkg_version_path <- function () {
     return (cm_path)
 }
 
-#' Ensure CRAN versions are released on GitHUb
+#' Extract data on releases of packages, both on CRAN and GitHub.
+#'
+#' @param CRAN_only If `TRUE`, return only those rows of `repo_data` which
+#' correspond to packages which are or were on CRAN; otherwise return all data.
+#' @return A `data.frame` with one row for each package, and columns containing
+#' information on the package including dates and version numbers of GitHub and
+#' CRAN releases (if any).
 #'
 #' @export
 registry_pkg_versions <- function (CRAN_only = TRUE) {
diff --git a/man/registry_pkg_versions.Rd b/man/registry_pkg_versions.Rd
index b05bafc..474a85c 100644
--- a/man/registry_pkg_versions.Rd
+++ b/man/registry_pkg_versions.Rd
@@ -2,10 +2,19 @@
 % Please edit documentation in R/pkg-versions.R
 \name{registry_pkg_versions}
 \alias{registry_pkg_versions}
-\title{Ensure CRAN versions are released on GitHUb}
+\title{Extract data on releases of packages, both on CRAN and GitHub.}
 \usage{
 registry_pkg_versions(CRAN_only = TRUE)
 }
+\arguments{
+\item{CRAN_only}{If `TRUE`, return only those rows of `repo_data` which
+correspond to packages which are or were on CRAN; otherwise return all data.}
+}
+\value{
+A `data.frame` with one row for each package, and columns containing
+information on the package including dates and version numbers of GitHub and
+CRAN releases (if any).
+}
 \description{
-Ensure CRAN versions are released on GitHUb
+Extract data on releases of packages, both on CRAN and GitHub.
 }