diff --git a/src/ol/format/geojsonformat.js b/src/ol/format/geojsonformat.js
index aa18754b7f..8f7d03007c 100644
--- a/src/ol/format/geojsonformat.js
+++ b/src/ol/format/geojsonformat.js
@@ -159,7 +159,7 @@ ol.format.GeoJSON.readPolygonGeometry_ = function(object) {
 /**
  * @param {ol.geom.Geometry} geometry Geometry.
  * @private
- * @return {GeoJSONObject} GeoJSON geometry.
+ * @return {GeoJSONGeometry|GeoJSONGeometryCollection} GeoJSON geometry.
  */
 ol.format.GeoJSON.writeGeometry_ = function(geometry) {
   var geometryWriter = ol.format.GeoJSON.GEOMETRY_WRITERS_[geometry.getType()];
@@ -302,7 +302,7 @@ ol.format.GeoJSON.GEOMETRY_READERS_ = {
 /**
  * @const
  * @private
- * @type {Object.<string, function(ol.geom.Geometry): GeoJSONObject>}
+ * @type {Object.<string, function(ol.geom.Geometry): (GeoJSONGeometry|GeoJSONGeometryCollection)>}
  */
 ol.format.GeoJSON.GEOMETRY_WRITERS_ = {
   'Point': ol.format.GeoJSON.writePointGeometry_,
@@ -456,7 +456,7 @@ ol.format.GeoJSON.prototype.readProjectionFromObject = function(object) {
  *
  * @function
  * @param {ol.Feature} feature Feature.
- * @return {ArrayBuffer|Node|Object|string} GeoJSON.
+ * @return {GeoJSONFeature} GeoJSON.
  * @api
  */
 ol.format.GeoJSON.prototype.writeFeature;
@@ -492,7 +492,7 @@ ol.format.GeoJSON.prototype.writeFeatureObject = function(feature) {
  *
  * @function
  * @param {Array.<ol.Feature>} features Features.
- * @return {ArrayBuffer|Node|Object|string} GeoJSON.
+ * @return {GeoJSONObject} GeoJSON.
  * @api
  */
 ol.format.GeoJSON.prototype.writeFeatures;
@@ -519,7 +519,7 @@ ol.format.GeoJSON.prototype.writeFeaturesObject = function(features) {
  *
  * @function
  * @param {ol.geom.Geometry} geometry Geometry.
- * @return {ArrayBuffer|Node|Object|string} GeoJSON.
+ * @return {GeoJSONGeometry|GeoJSONGeometryCollection} GeoJSON.
  * @api
  */
 ol.format.GeoJSON.prototype.writeGeometry;
diff --git a/src/ol/format/gmlformat.js b/src/ol/format/gmlformat.js
index df9e1b8b78..1dd843cb23 100644
--- a/src/ol/format/gmlformat.js
+++ b/src/ol/format/gmlformat.js
@@ -1689,7 +1689,7 @@ ol.format.GML.prototype.writeGeometryNode = function(geometry) {
  *
  * @function
  * @param {Array.<ol.Feature>} features Features.
- * @return {ArrayBuffer|Node|Object|string} Result.
+ * @return {Node} Result.
  * @api
  */
 ol.format.GML.prototype.writeFeatures;
diff --git a/src/ol/format/gpxformat.js b/src/ol/format/gpxformat.js
index 1e1b9f5d07..af48c40316 100644
--- a/src/ol/format/gpxformat.js
+++ b/src/ol/format/gpxformat.js
@@ -845,7 +845,7 @@ ol.format.GPX.GPX_SERIALIZERS_ = ol.xml.makeStructureNS(
  *
  * @function
  * @param {Array.<ol.Feature>} features Features.
- * @return {ArrayBuffer|Node|Object|string} Result.
+ * @return {Node} Result.
  * @api
  */
 ol.format.GPX.prototype.writeFeatures;
diff --git a/src/ol/format/kmlformat.js b/src/ol/format/kmlformat.js
index f598188fc5..20f0fef1c6 100644
--- a/src/ol/format/kmlformat.js
+++ b/src/ol/format/kmlformat.js
@@ -2494,7 +2494,7 @@ ol.format.KML.OUTER_BOUNDARY_NODE_FACTORY_ =
  *
  * @function
  * @param {Array.<ol.Feature>} features Features.
- * @return {ArrayBuffer|Node|Object|string} Result.
+ * @return {Node} Result.
  * @api
  */
 ol.format.KML.prototype.writeFeatures;
diff --git a/src/ol/style.jsdoc b/src/ol/style.jsdoc
new file mode 100644
index 0000000000..ed02b4dbdf
--- /dev/null
+++ b/src/ol/style.jsdoc
@@ -0,0 +1,3 @@
+/**
+ * @namespace ol.style
+ */