diff --git a/metadata-readme/Historical-postcards-metadata-readme.md b/metadata-readme/Historical-postcards-metadata-readme.md
index 242930d4d4514fc16f768d2665cec7f840c4cbfe..5a0d72516b2d3230ef4134e59101dbd5d1f249a7 100644
--- a/metadata-readme/Historical-postcards-metadata-readme.md
+++ b/metadata-readme/Historical-postcards-metadata-readme.md
@@ -1,35 +1,37 @@
-This Readme offers explanations for all attributes of the metadata csv table to the dataset "Historical Postcards"
+This Readme offers explanations for all attributes of the metadata csv table to the dataset "Historical Postcards". 
+The frequency attribute can have the value "all", "most", "some" or "none". It gives you an overview of how often a value is to be expected for the attribute explained in relation to the whole dataset.
+Please note that the CSV is an export of keys and values of the Relational Database Kawan used for editing the metadata. Some values may have a false attribution. Some data cleaning may be necessary.
 
 | attribute | explanation | frequency | datatype |
 | ---- | ---- | ---- | ---- |
-| akon_id | id (shelfmark) of the document | all | string |    
+| akon_id | id of the document; please refer to this id | all | string |    
 | id | internal numerical id | all | integer |
 | altitude | geolocation altitude | some | integer |
-| building | has literal, if building was tagged in metadata editing | some | string |
-| city | has literal, if city was tagged in metadata editing | most | string |
+| building | name of a building (human artifact) | some | string |
+| city | placename (city) | most | string |
 | color | True for color postcards | all | boolean |
-| comment | has literal for | most |     
-| mountain | has literal, if mountain was tagged in metadata editing | some | string |
-| other | has literal for any other tags | some | string |
-| photographer | has literal, if photographer was identified. Name usually in the form \{forename surname\}. Not linked to GND | some | string |
-| publisher | has literal, if publisher was identified. Name usually in the form \{forename surname\} OR \{surname\}. Not linked to GND | some | string |
-| publisher_place | has literal, if publication place was identified. Not linked to Geonames or GND | some | string |
-| region | | some | string |
-| water_body | | some | string |
-| year | | some | string |
-| inventory_number | | some | string |
-| signature | | some | string |
-| revision_date | | some | string |
-| date | | some | string |
-| feature_class | | some | string |
-| feature_code | | some | string |
-| geoname_id | | some | string |
-| latitude | | some | string |
-| longitude | | some | string |
-| name | | some | string |
-| country_id | | some | string |
+| comment | date or determined date; "date gel" stands for "date gelaufen", "gelaufen" means that year the postcards was sent, usually marked by a postal stemp; "v. date" stands for "vor ..." (engl. before), means a date ante quem | most | string |   
+| mountain | name of mountain, not linked to authority file | some | string |
+| other | any other tags | some | string |
+| photographer | personal name or corporate name, not linked to authority file. Name usually in the form \{forename surname\}  | some | string |
+| publisher | personal name or corporate name, not linked to authority file. Name usually in the form \{forename surname\} OR \{surname\} | some | string |
+| publisher_place | placename, not linked to authority file (GND, Geonames) | some | string |
+| region |  | some | string |
+| water_body | name of water_body, not linked to authority file (GND, Geonames) | some | string |
+| year | exact year the postcard can be dated. If no exact date is available, a value can be found for the "comment" attribute | some | integer |
+| inventory_number | an internal inventory number usually in the form of \{number/number section\} | some | string |
+| signature | informations on attributions to former collections or subcollections; may contain information on provenance; please note the abbrevations | some | string |
+| revision_date | timestamp of last revision of metadata in the RDB Kawan | most | date |
+| date | combination of year and comment, "gelaufen" and "vor" are usually not abbreviated in this field | most | string |
+| feature_class | code of the (GeoNames export codes)[https://www.geonames.org/export/codes.html]  | most | string |
+| feature_code | code of the (GeoNames export codes)[https://www.geonames.org/export/codes.html] | most | string |
+| geoname_id | GeoName identifier of placename (attribute: "name"), if a placename has been identified | most | float |
+| latitude |  | most | float |
+| longitude | | most | float |
+| name | placename of place identified (GeoName ID is in attribute "geoname_id") | most | string |
+| country_id | code for country (modern) within which borders the identified placename lies today; the form is ISO-3166 Alpha-2 code | most | string |
 | admin_name_1 | | some | string |
 | admin_code_1 | | some | string |
-| geo | | some | string |
+| geo |  Tuple of latitude comma longitude | most | string |
 | download_link | url to the full resolution image | all | string |
-| download_link_256x256 | url to the thumbnail image with resolution 256x256 px | all | string |
\ No newline at end of file
+| download_link_256x256 | url to the thumbnail image with resolution 256x256 px | all | string |