diff --git a/Database.md b/Database.md
index 64f3523..a69f835 100644
--- a/Database.md
+++ b/Database.md
@@ -101,4 +101,11 @@ In addition, the relation types (the kind of relationship) are precisely defined
     * 'value': for example der url of a doi
     * 'relation': the following relation types are allowed in TETHYS: 'IsSupplementTo', 'IsSupplementedBy', 'IsContinuedBy', 'Continues', 'IsNewVersionOf', 'IsPartOf', 'HasPart', 'Compiles', 'IsVariantFormOf'
 
+<br>
 
+## TETHYS lookup tables
+![title](./tethys_lookup.png)
+
+* **document_xml_cache**:
+* **mime_types**:
+* **languages**:
\ No newline at end of file
diff --git a/tethys_lookup.png b/tethys_lookup.png
new file mode 100644
index 0000000..a253fa8
Binary files /dev/null and b/tethys_lookup.png differ