diff --git a/src/sampleconf/mimeconf b/src/sampleconf/mimeconf
index 2e67f545..15b32c06 100644
--- a/src/sampleconf/mimeconf
+++ b/src/sampleconf/mimeconf
@@ -1,7 +1,15 @@
 # (C) 2004 J.F.Dockes
 
-# Associations of mime types to processing filters ([index] section).
-# Other sections describe auxiliary properties associated to the mime types.
+# This file contains most of the data which determines how we
+# handle the different mime types (also see the "mimeview" file).
+# Sections:
+# top-level: Decompression parameters. Should not be at top-level, historical.
+# [index] : Associations of mime types to the filters that translate them
+#      to plain text or html.
+# [icons] : Associations of mime types to result list icons (GUI)
+# [categories] : groupings of mime types (media, text, message etc.)
+# [guifilters] : defines the filtering checkboxes in the GUI. Uses the
+#   above categories by default
 
 ## #######################################
 # Decompression: these types need a first pass to create a temp file to
diff --git a/src/sampleconf/mimemap b/src/sampleconf/mimemap
index f46c9266..541a309e 100644
--- a/src/sampleconf/mimemap
+++ b/src/sampleconf/mimemap
@@ -36,6 +36,9 @@
 .php = text/html
 .ics = text/calendar
 
+# .eml is used as an extension by several mail apps for a single message
+# saved in raw MIME format. Mainly used here to get Thunderbird to open an
+# extracted message.
 .eml = message/rfc822
 
 .pdf = application/pdf