diff --git a/cave_data/2007-06.html b/cave_data/1623-2007-06.html
similarity index 88%
rename from cave_data/2007-06.html
rename to cave_data/1623-2007-06.html
index a15d438b2..946fcf4cd 100644
--- a/cave_data/2007-06.html
+++ b/cave_data/1623-2007-06.html
@@ -10,7 +10,7 @@
 <body>
 <cave>
 <non_public>False</non_public><!-- 'False' or 'True'. True if the cave should only be visible to logged-in users. Caves are normally public, so enter 'False' unless you know otherwise. -->
-<caveslug>2007-06</caveslug><!--(Required). Internal I.D. used to refer to this cave in entrance data files. Typically the same as the filebase, e.g. '1623-195'  -->
+<caveslug>1623-2007-06</caveslug><!--(Required). Internal I.D. used to refer to this cave in entrance data files. Typically the same as the filebase, e.g. '1623-195'  -->
 <official_name></official_name><!-- Name of the cave (normally in German)  Use &uuml; for u+Umlaut and &ouml; for o+umlaut eg H&ouml;hle for Hohle and Gl&uuml;ck for Gluck-->
 <area>1623</area><!-- the CUCC-defined areas shown in http://expo.survex.com/areas.htm -->
 <kataster_code></kataster_code><!-- 'length-or-depth/type exploration'
@@ -31,6 +31,11 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
 <kataster_number></kataster_number> <!-- (Either this or unofficial_number is required). Official number in Austrian kataster if one has been allocated  -->
 <unofficial_number>2007-06</unofficial_number><!-- (Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
 
+<entrance>
+  <entranceslug>1623-2007-06</entranceslug><!-- Internal ID to refer to each entrance instance in the entrance files (typically the same as that filename (e.g. 1623-161c). Matches the 'slug' field in the entrance file -->
+  <letter></letter><!--Leave blank for single-entrance cave. If there is more than one entrace then the letter needs to be given. Generally matches the entranceslug ID.  -->
+</entrance>
+
 <explorers>Andrew Atkinson, Becka Lawson</explorers><!-- 'CUCC Expo' and year(s) of exploration. To distinguish from caves explored by foreign groups. Individual names can be given too if it was a small cave. -->
 <underground_description>2007-06 Elev 1810m 36931 83264 20m deep surface shaft - possible way off from base, to SE.</underground_description><!-- Underground description. (description of approach and entrance goes in entrance file). For a small cave this will be the entire description. For larger caves it will be the front page of the description, or a short intro, containing links to other pages with the cave description in, or even nothing but a link. -->
 <equipment></equipment><!-- For a small cave, summary of gear needed to descend. For longer caves it could be blank, a table, or just refer to the description/topos. Leave blank if this info is in the description. -->
diff --git a/entrance_data/2007-06.html b/entrance_data/2007-06.html
deleted file mode 100644
index e88018e4f..000000000
--- a/entrance_data/2007-06.html
+++ /dev/null
@@ -1,54 +0,0 @@
-<!DOCTYPE html>
-<!-- Only put one entrance in this file -->
-<!-- This file is generated using the form documented at /handbook/survey/caveentry.html -->
-<!-- If you edit this file by hand, make sure you update the database by doing a full data import -->
-
-    <!-- See http://expo.survex.com/handbook/survey/caveentryfields.html for current details on filling in this form -->
-    <!-- there is 1 required field: slug. The entrance will not appear without that. -->
-    <!-- ALWAYS use &uuml; for u+Umlaut and &ouml; for o+umlaut eg H&ouml;hle for Hohle and Gl&uuml;ck for Gluck-->
-
-<html lang="en">
-<head>
-<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
-</head>
-<body>
-<entrance>
-<non_public>False</non_public>
-<slug>2007-06</slug>
-<name></name>
-<entrance_description></entrance_description>
-<explorers></explorers>
-<map_description></map_description>
-<location_description></location_description>
-<approach></approach>
-<underground_description>20m deep surface shaft</underground_description>
-<photo></photo>
-<!-- marking options: P  = Paint,
-                      P? = Paint (?),
-                      T  = Tag,
-                      T? = Tag (?),
-                      R  = Retagged,
-                      S  = Spit,
-                      S? = Spit (?),
-                      U  = Unmarked,
-                      ?  = Unknown" -->
-<marking>?</marking> 
-<marking_comment></marking_comment>
-<!-- findability options: ? = To be confirmed ...,
-                          S = Surveyed,
-                          L = Lost,
-                          R = Refindable" -->
-<findability></findability>
-<findability_description></findability_description>
-<alt>1810</alt>
-<northing>36931</northing>
-<easting>83264</easting> 
-<tag_station></tag_station>
-<exact_station></exact_station>
-<other_station></other_station>
-<other_description></other_description>
-<bearings></bearings>
-<url></url>
-</entrance>
-</body>
-</html>
