diff --git a/cave_data/1623-88F.html b/cave_data/1623-88F-01.html
similarity index 84%
rename from cave_data/1623-88F.html
rename to cave_data/1623-88F-01.html
index d6566b00f..43d8c91f4 100644
--- a/cave_data/1623-88F.html
+++ b/cave_data/1623-88F-01.html
@@ -17,7 +17,6 @@ the form documented at
 
 <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>1623-88F</caveslug>--> <!-- Ignored. No longer required, we use the filename instead e.g. 1623-315 for 1623-315.html  -->
 <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><!-- e.g. "1623" -->
 <kataster_code></kataster_code><!-- 'length-or-depth/type exploration'
@@ -36,10 +35,10 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
     +   erforscht (exploration considered complete)
  -->
 <kataster_number></kataster_number> <!-- (Either this or unofficial_number is required). Official number in Austrian kataster if one has been allocated  -->
-<unofficial_number>88F</unofficial_number><!-- (This is any name. Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
+<unofficial_number>88F-01</unofficial_number><!-- (This is any name. Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
 
 <entrance>
-  <entranceslug>1623-88F</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 -->
+  <entranceslug>1623-88F-01</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 entrance then the letter needs to be given. Must match the entranceslug ID.  -->
 </entrance>
 
@@ -57,9 +56,7 @@ It's probably GSCB as the paint said VSS2, which seems to be some sort of nickna
 meaning something like "the mad spit hammerers"
 <br>
 i'd guess 88F is their 6th entrance from 1988 - I think we've also seen 88H</p></notes><!-- Normally empty, but place for anything else that should be noted, such as info on cave maybe being a duplicate, or lost, and whether a kataster form has been sent to Austria for this cave -->
-<length></length><!-- Cave length. Can be left blank and system should fill it in automatically from survey data (it doesn't yet) -->
-<depth></depth><!--Cave depth. Can be left blank and system should fill it in automatically from survey data (it doesn't yet)  -->
-<extent></extent>
+
 
 <description_file></description_file><!-- Path of top-level description file for this cave, when a separate file is used. Otherwise blank. -->
 </cave>
diff --git a/cave_data/1623-88H.html b/cave_data/1623-88H-01.html
similarity index 83%
rename from cave_data/1623-88H.html
rename to cave_data/1623-88H-01.html
index e1cd3edc4..0eb9ff533 100644
--- a/cave_data/1623-88H.html
+++ b/cave_data/1623-88H-01.html
@@ -17,7 +17,6 @@ the form documented at
 
 <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>1623-88H</caveslug>--> <!-- Ignored. No longer required, we use the filename instead e.g. 1623-315 for 1623-315.html  -->
 <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><!-- e.g. "1623" -->
 <kataster_code></kataster_code><!-- 'length-or-depth/type exploration'
@@ -36,10 +35,10 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
     +   erforscht (exploration considered complete)
  -->
 <kataster_number></kataster_number> <!-- (Either this or unofficial_number is required). Official number in Austrian kataster if one has been allocated  -->
-<unofficial_number>88H</unofficial_number><!-- (This is any name. Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
+<unofficial_number>88H-01</unofficial_number><!-- (This is any name. Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
 
 <entrance>
-  <entranceslug>1623-88H</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 -->
+  <entranceslug>1623-88H-01</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 entrance then the letter needs to be given. Must match the entranceslug ID.  -->
 </entrance>
 
@@ -52,9 +51,7 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
 <notes>Is this an entrance to 1623/88 Larchenschacht ?
 <p><a href="/others/gscb/index.htm">GSCB</a>
   <p>Seems unlikely, as 88F is definitely a long way away from 1623-88, but we have no location for this cave 88H so the point is moot.</notes><!-- Normally empty, but place for anything else that should be noted, such as info on cave maybe being a duplicate, or lost, and whether a kataster form has been sent to Austria for this cave -->
-<length></length><!-- Cave length. Can be left blank and system should fill it in automatically from survey data (it doesn't yet) -->
-<depth></depth><!--Cave depth. Can be left blank and system should fill it in automatically from survey data (it doesn't yet)  -->
-<extent></extent>
+
 
 <description_file></description_file><!-- Path of top-level description file for this cave, when a separate file is used. Otherwise blank. -->
 </cave>
diff --git a/cave_data/1623-Blaubeer.html b/cave_data/1623-BLB-01.html
similarity index 81%
rename from cave_data/1623-Blaubeer.html
rename to cave_data/1623-BLB-01.html
index 66dc44dc5..04003af47 100644
--- a/cave_data/1623-Blaubeer.html
+++ b/cave_data/1623-BLB-01.html
@@ -17,8 +17,7 @@ the form documented at
 
 <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>1623-Blaubeer</caveslug><!--(Ignored). 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-->
+<official_name>Blaubeer</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><!-- e.g. "1623" -->
 <kataster_code></kataster_code><!-- 'length-or-depth/type exploration'
 code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast.htm
@@ -36,11 +35,10 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
     +   erforscht (exploration considered complete)
  -->
 <kataster_number></kataster_number> <!-- (Either this or unofficial_number is required). Official number in Austrian kataster if one has been allocated  -->
-<unofficial_number>Blaubeer</unofficial_number><!-- (Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
+<unofficial_number>BLB-01</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-Blaubeer</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 -->
-  <!-- DEBUG  1623-Blaubeer+1623-Blaubeer 'Z' == -->
+  <entranceslug>1623-BLB-01</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>
 
@@ -61,7 +59,6 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
 <extent></extent>
 
 <description_file></description_file><!-- Path of top-level description file for this cave, when a separate file is used. Otherwise blank. -->
-<url>1623/blaubeer/blaubeer.html</url><!-- (Required). Relative URL of this cave. i.e the URL this cave appears at on the website, not including 'https://expo.survex.com/. Normally area/cavenum., e.g ('1623/000')-->
 </cave>
 </body>
 </html>
diff --git a/cave_data/1623-Haldenloch.html b/cave_data/1623-HLD-01.html
similarity index 82%
rename from cave_data/1623-Haldenloch.html
rename to cave_data/1623-HLD-01.html
index 2313cb732..3ff25236d 100644
--- a/cave_data/1623-Haldenloch.html
+++ b/cave_data/1623-HLD-01.html
@@ -17,9 +17,7 @@ the form documented at
 
 <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>1623-Haldenloch</caveslug><!--(Ignored). 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>Haldenloch</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><!-- e.g. "1623" -->
 <kataster_code></kataster_code><!-- 'length-or-depth/type exploration'
 code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast.htm
 
@@ -36,10 +34,10 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
     +   erforscht (exploration considered complete)
  -->
 <kataster_number></kataster_number> <!-- (Either this or unofficial_number is required). Official number in Austrian kataster if one has been allocated  -->
-<unofficial_number>Haldenloch</unofficial_number><!-- (This is any name. Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
+<unofficial_number>HLD-01</unofficial_number><!-- (This is any name. 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-haldenloch</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 -->
+  <entranceslug>1623-HLD-01</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>
 
@@ -56,9 +54,6 @@ No description or location</underground_description><!-- Underground description
 <kataster_status></kataster_status>
 Blank if not, or notes about status such as 'surveyed, but no entrance fix so not yet in dataset'. -->
 <notes>_Survex file found in loser repo</notes><!-- Normally empty, but place for anything else that should be noted, such as info on cave maybe being a duplicate, or lost -->
-<length></length><!-- Cave length. Can be left blank and system should fill it in automatically from survey data (it doesn't yet) -->
-<depth></depth><!--Cave depth. Can be left blank and system should fill it in automatically from survey data (it doesn't yet)  -->
-<extent></extent>
 
 <description_file></description_file><!-- Path of top-level description file for this cave, when a separate file is used. Otherwise blank. -->
 </cave>
diff --git a/cave_data/1623-Juttahoehle.html b/cave_data/1623-JTT-01.html
similarity index 78%
rename from cave_data/1623-Juttahoehle.html
rename to cave_data/1623-JTT-01.html
index 90a659969..12d625317 100644
--- a/cave_data/1623-Juttahoehle.html
+++ b/cave_data/1623-JTT-01.html
@@ -17,9 +17,7 @@ the form documented at
 
 <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>1623-Juttahoehle</caveslug><!--(Ignored). 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><!-- e.g. "1623" -->
+<official_name>Juttahoehle</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-->
 <kataster_code></kataster_code><!-- 'length-or-depth/type exploration'
 code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast.htm
 
@@ -36,10 +34,10 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
     +   erforscht (exploration considered complete)
  -->
 <kataster_number></kataster_number> <!-- (Either this or unofficial_number is required). Official number in Austrian kataster if one has been allocated  -->
-<unofficial_number>Juttahoehle</unofficial_number><!-- (Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
+<unofficial_number>JTT-01</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-Juttahoehle</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 -->
+  <entranceslug>1623-JTT-01</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>
 
@@ -62,12 +60,8 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
 <underground_centre_line></underground_centre_line><!-- 'In dataset' if it is in the survex dataset. Blank if not, or notes about status such as 'surveyed, but no entrance fix so not yet in dataset'. -->
 <notes>Surface survey on same date:
 surface/1623/vfhmdata</notes><!-- Normally empty, but place for anything else that should be noted, such as info on cave maybe being a duplicate, or lost -->
-<length></length><!-- Cave length. Can be left blank and system should fill it in automatically from survey data (it doesn't yet) -->
-<depth></depth><!--Cave depth. Can be left blank and system should fill it in automatically from survey data (it doesn't yet)  -->
-<extent></extent>
 
 <description_file></description_file><!-- Path of top-level description file for this cave, when a separate file is used. Otherwise blank. -->
-<url>1623/juttahoehle/juttahoehle.html</url><!-- (Required). Relative URL of this cave. i.e the URL this cave appears at on the website, not including 'https://expo.survex.com/. Normally area/cavenum., e.g ('1623/000')-->
 </cave>
 </body>
 </html>
diff --git a/cave_data/1623-rentner.html b/cave_data/1623-RNT-01.html
similarity index 81%
rename from cave_data/1623-rentner.html
rename to cave_data/1623-RNT-01.html
index 98b061aa3..985106059 100644
--- a/cave_data/1623-rentner.html
+++ b/cave_data/1623-RNT-01.html
@@ -1,12 +1,14 @@
 <!DOCTYPE html>
-<!-- This file is generated by troggle on Nov. 2, 2023, 8:15 p.m. UTC using the form documented at /handbook/survey/caveentry.html -->
+<!-- Tform documented at /handbook/survey/caveentry.html -->
 <!-- Only put one cave in this file -->
 <!-- If you edit this 1623-nnn.html file by hand, and manually upload it to the server using git,
 make sure you update the database by doing a full data import. If you edit it using the online form
 though, you do not need to do a data import as it happens automatically -->
 <!-- ALTERNATIVELY you can download an example template from expoweb/templates/cave_data.html -->
 <html lang="en">
-<head><title>Rentner Express</title></head>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
+</head>
 <body>
 <b>This file is generated by troggle</b> on Nov. 2, 2023, 8:15 p.m. UTC using the form documented at
 the form documented at 
@@ -33,12 +35,11 @@ code used in the Austrian kataster e.g '1/S +' - https://expo/.survex.com/katast
     +   erforscht (exploration considered complete)
  -->
 <kataster_number></kataster_number> <!-- (Either this or unofficial_number is required). Official number in Austrian kataster if one has been allocated  -->
-<unofficial_number>rentner</unofficial_number><!-- (Either this or kataster_number is required). Initial temporary cave ID used until kataster number is allocated e.g. '2012-DD-01'-->
+<unofficial_number>RNT-01</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-rentner</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 -->
-  <!-- DEBUG  1623-rentner+1623-rentner 'Z' == -->
-  <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.  -->
+  <entranceslug>1623-RNT-01</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></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. -->
@@ -69,6 +70,5 @@ schwingerclub
 <extent></extent>
 
 <description_file></description_file><!-- Path of top-level description file for this cave, when a separate file is used. Otherwise blank. -->
-<url>1623/rentner/rentner.html</url><!-- (Required). Relative URL of this cave. i.e the URL this cave appears at on the website, not including 'https://expo.survex.com/. Normally area/cavenum., e.g ('1623/000')-->
 </cave></body>
 </html>
diff --git a/entrance_data/1623-88F.html b/entrance_data/1623-88F-01.html
similarity index 98%
rename from entrance_data/1623-88F.html
rename to entrance_data/1623-88F-01.html
index efc94e982..ff7e298a1 100644
--- a/entrance_data/1623-88F.html
+++ b/entrance_data/1623-88F-01.html
@@ -8,7 +8,6 @@
 <body>
 <entrance>
 <non_public>False</non_public>
-<slug>1623-88F</slug>
 <name></name>
 <entrance_description></entrance_description>
 <explorers></explorers>
diff --git a/entrance_data/1623-88H.html b/entrance_data/1623-88H-01.html
similarity index 98%
rename from entrance_data/1623-88H.html
rename to entrance_data/1623-88H-01.html
index 4256dfcb7..947564ecc 100644
--- a/entrance_data/1623-88H.html
+++ b/entrance_data/1623-88H-01.html
@@ -8,7 +8,6 @@
 <body>
 <entrance>
 <non_public>False</non_public>
-<slug>1623-88H</slug>
 <name></name>
 <entrance_description></entrance_description>
 <explorers></explorers>
diff --git a/entrance_data/1623-Blaubeer.html b/entrance_data/1623-BLB-01.html
similarity index 96%
rename from entrance_data/1623-Blaubeer.html
rename to entrance_data/1623-BLB-01.html
index 9843d9e69..a14137444 100644
--- a/entrance_data/1623-Blaubeer.html
+++ b/entrance_data/1623-BLB-01.html
@@ -19,7 +19,6 @@ though, you do not need to do a data import as it happens automatically -->
 <br>
 <entrance>
 <non_public>False</non_public>
-<slug>1623-Blaubeer</slug> <!-- one entrance and one slug per entrance_data file -->
 <name></name>
 <entrance_description></entrance_description>
 <explorers></explorers>
diff --git a/entrance_data/1623-haldenloch.html b/entrance_data/1623-HLD-01.html
similarity index 96%
rename from entrance_data/1623-haldenloch.html
rename to entrance_data/1623-HLD-01.html
index 10fb6a60b..835f4729d 100644
--- a/entrance_data/1623-haldenloch.html
+++ b/entrance_data/1623-HLD-01.html
@@ -19,7 +19,6 @@ though, you do not need to do a data import as it happens automatically -->
 <br>
 <entrance>
 <non_public>False</non_public>
-<slug>1623-haldenloch</slug> <!-- one entrance and one slug per entrance_data file -->
 <name></name>
 <entrance_description>Default assumed entrance</entrance_description>
 <explorers></explorers>
diff --git a/entrance_data/1623-Juttahoehle.html b/entrance_data/1623-JTT-01.html
similarity index 96%
rename from entrance_data/1623-Juttahoehle.html
rename to entrance_data/1623-JTT-01.html
index d879f8889..684c831f9 100644
--- a/entrance_data/1623-Juttahoehle.html
+++ b/entrance_data/1623-JTT-01.html
@@ -19,7 +19,6 @@ though, you do not need to do a data import as it happens automatically -->
 <br>
 <entrance>
 <non_public>False</non_public>
-<slug>1623-Juttahoehle</slug> <!-- one entrance and one slug per entrance_data file -->
 <name></name>
 <entrance_description></entrance_description>
 <explorers></explorers>
diff --git a/entrance_data/1623-rentner.html b/entrance_data/1623-RNT-01.html
similarity index 96%
rename from entrance_data/1623-rentner.html
rename to entrance_data/1623-RNT-01.html
index 03e231583..17e26df2b 100644
--- a/entrance_data/1623-rentner.html
+++ b/entrance_data/1623-RNT-01.html
@@ -19,7 +19,6 @@ though, you do not need to do a data import as it happens automatically -->
 <br>
 <entrance>
 <non_public>False</non_public>
-<slug>1623-rentner</slug> <!-- one entrance and one slug per entrance_data file -->
 <name></name>
 <entrance_description></entrance_description>
 <explorers></explorers>