diff --git a/screening/dist/etc/service.properties b/screening/dist/etc/service.properties
index fb363b46c7be2e6e2516a43c8eee78ce55f50516..ab1c6e03b6faa49311ee1f8a1fcbbaecff8c38c5 100644
--- a/screening/dist/etc/service.properties
+++ b/screening/dist/etc/service.properties
@@ -234,14 +234,26 @@ merged-channels-images.type-extractor.data-set-type = HCS_IMAGE
 merged-channels-images.type-extractor.is-measured = true
 
 merged-channels-images.storage-processor = ch.systemsx.cisd.openbis.dss.etl.PlateStorageProcessor
+# Should the thumbnails be generated? 
+# It slows down the dataset registration, but increases the performance when the user wants to see the image. 
+# Can be 'true' or 'false', 'false' is the default value
 merged-channels-images.storage-processor.generate-thumbnails = true
+# Thumbnails size in pixels
 #merged-channels-images.storage-processor.thumbnail-max-width = 300
 #merged-channels-images.storage-processor.thumbnail-max-height = 200
+# Names of the channels in which images have been acquired.
 merged-channels-images.storage-processor.channel-names = green, blue
+# Format: [width]>x[height], e.g. 3x4. Specifies the grid into which a microscope divided the well to acquire images.
 merged-channels-images.storage-processor.well_geometry = 3x3
-merged-channels-images.storage-processor.file-extractor = ch.systemsx.cisd.openbis.dss.etl.lmc.HCSImageFileExtractor
+# implementation of the IHCSImageFileExtractor interface which maps images to the location on the plate and particular channel
+# Here: the extractor requireds that each image name should adhere to the schema:
+#     <any-text>_<plate-code>_<well-code>_<tile-code>_<channel-name>.<allowed-image-extension>
+merged-channels-images.storage-processor.file-extractor = ch.systemsx.cisd.openbis.dss.etl.HCSImageFileExtractor
+# specification of the imaging db
 merged-channels-images.storage-processor.data-source = imaging-db
-# Available values: RED, GREEN or BLUE 
+# Optional comma separated list of color components. 
+# Available values: RED, GREEN or BLUE. 
+# If specified then the channels are extracted from the color components and override 'file-extractor' results.
 merged-channels-images.storage-processor.extract-single-image-channels = GREEN, BLUE
 
 # ---------------------------------------------------------------------------