diff --git a/okapi/core/OkapiServiceRunner.php b/okapi/core/OkapiServiceRunner.php
index a1d0abba..250c0eac 100644
--- a/okapi/core/OkapiServiceRunner.php
+++ b/okapi/core/OkapiServiceRunner.php
@@ -43,6 +43,13 @@ class OkapiServiceRunner
         'services/caches/formatters/garmin',
         'services/caches/formatters/ggz',
         'services/caches/map/tile',
+        'services/lists/add_caches',
+        'services/lists/create',
+        'services/lists/delete',
+        'services/lists/get_caches',
+        'services/lists/remove_caches',
+        'services/lists/query',
+        'services/lists/update',
         'services/logs/capabilities',
         'services/logs/delete',
         'services/logs/edit',
diff --git a/okapi/services/lists/add_caches/WebService.php b/okapi/services/lists/add_caches/WebService.php
new file mode 100644
index 00000000..5c3894bf
--- /dev/null
+++ b/okapi/services/lists/add_caches/WebService.php
@@ -0,0 +1,67 @@
+<?php
+
+namespace okapi\services\lists\add_caches;
+
+use okapi\core\Db;
+use okapi\core\Okapi;
+use okapi\core\Request\OkapiRequest;
+use okapi\Settings;
+use okapi\core\Exception\InvalidParam;
+
+class WebService
+{
+    public static function options()
+    {
+        return array(
+            'min_auth_level' => 3
+        );
+    }
+
+    public static function call(OkapiRequest $request)
+    {
+        $result = array(
+            'success' => false
+        );
+
+        $user_id = $request->token->user_id;
+
+        $listId     = $request->get_parameter('list_id');
+        $cacheCodes = $request->get_parameter('cache_codes');
+
+        if (empty($listId)) {
+            throw new InvalidParam('list_id', 'list_id is mandatory and must not be empty.');
+        }
+
+        if (empty($cacheCodes)) {
+            throw new InvalidParam('cache_codes', 'cache_codes is mandatory and must not be empty.');
+        }
+
+        $cacheCodesArray = array_unique(explode('|', $cacheCodes));
+
+        // Check the length
+        if (count($cacheCodesArray) > 500) {
+            throw new InvalidParam('cache_codes', 'The number of cache codes exceeds the limit of 500.');
+        }
+
+        // Escape cache codes and build the SQL query
+        $escapedCacheCodes = implode("','", array_map('\okapi\core\Db::escape_string', $cacheCodesArray));
+
+        // Fetch cache_ids from the caches table using INSERT IGNORE
+        $rs = Db::query("
+            INSERT IGNORE INTO cache_list_items (cache_list_id, cache_id)
+            SELECT '$listId', cache_id
+            FROM caches
+            WHERE wp_oc IN ('$escapedCacheCodes')
+        ");
+
+        $insertedCount = $rs->rowCount(); // Get the number of affected rows
+
+        $result = array(
+            'success'     => true,
+            'added_count' => $insertedCount
+        );
+
+        return Okapi::formatted_response($request, $result);
+    }
+}
+
diff --git a/okapi/services/lists/add_caches/docs.xml b/okapi/services/lists/add_caches/docs.xml
new file mode 100644
index 00000000..5146b97c
--- /dev/null
+++ b/okapi/services/lists/add_caches/docs.xml
@@ -0,0 +1,23 @@
+<xml>
+    <brief>Add Caches To List</brief>
+    <issue-id>627</issue-id>
+    <desc>
+        <p>This method is used to add geocaches to an existing list.</p>
+    </desc>
+    <req name="list_id">
+        <p>The id of a list. List IDs can be obtained by ::service/lists/query</p>
+    </req>
+    <req name="cache_codes">
+    <p>A pipe separated list of cache_codes to be added to the list.</p>
+    <p>Up to 500 geoaches can be added to the list by one request to
+    this method</p>
+    </req>
+    <common-format-params/>
+    <returns>
+        <p>A dictionary of the following structure:</p>
+        <ul>
+            <li>success - true</li>
+            <li>added_count - number of geocaches added to the list</li>
+        </ul>
+    </returns>
+</xml>
diff --git a/okapi/services/lists/create/WebService.php b/okapi/services/lists/create/WebService.php
new file mode 100644
index 00000000..9e949d57
--- /dev/null
+++ b/okapi/services/lists/create/WebService.php
@@ -0,0 +1,93 @@
+<?php
+
+namespace okapi\services\lists\create;
+
+use okapi\core\Db;
+use okapi\core\Okapi;
+use okapi\core\Request\OkapiRequest;
+use okapi\Settings;
+use okapi\core\Exception\InvalidParam;
+
+class WebService
+{
+
+    public static function options()
+    {
+        return array(
+            'min_auth_level' => 3
+        );
+    }
+
+    public static function call(OkapiRequest $request)
+    {
+        $result = array(
+            'success' => false
+        );
+
+        if (Settings::get('OC_BRANCH') == 'oc.de')
+        {
+            $user_id = $request->token->user_id;
+
+            $listName        = $request->get_parameter('list_name');
+            $listDescription = $request->get_parameter('list_description');
+            $listStatus      = $request->get_parameter('list_status');
+            $isWatched       = $request->get_parameter('is_watched');
+            $listPassword    = $request->get_parameter('list_password');
+
+            if (empty($listName)) {
+                throw new InvalidParam('list_name', 'list_name is mandatory and must not be empty.');
+            }
+
+            $insertFields = array(
+                'name' => Db::escape_string($listName),
+                'user_id' => Db::escape_string($user_id)
+            );
+
+            if (!empty($listDescription)) {
+                $insertFields['description'] = Db::escape_string($listDescription);
+            }
+
+            if ($listStatus !== null && $listStatus !== '') {
+                $listStatus = (int)$listStatus;
+                if (!in_array($listStatus, [0, 2, 3])) {
+                    throw new InvalidParam('list_status', 'list_status must be a valid value (0, 2, 3).');
+                }
+                $insertFields['is_public'] = $listStatus;
+
+                // Handle list_password only if list_status is 0 (private)
+                if ($listStatus == 0) {
+                    if (isset($listPassword) && $listPassword !== '') {
+                        $insertFields['password'] = substr(Db::escape_string($listPassword), 0, 16);
+                    }
+                }
+            }
+
+            $columns = implode(', ', array_keys($insertFields));
+            $values = "'" . implode("', '", $insertFields) . "'";
+
+            $insertQuery = "INSERT INTO cache_lists ($columns) VALUES ($values)";
+            Db::query($insertQuery);
+
+            $listId = Db::last_insert_id();
+
+            // Handle is_watched
+            if ($isWatched !== null && $isWatched !== '') {
+                $isWatched = (int)$isWatched;
+                if (!in_array($isWatched, [0, 1])) {
+                    throw new InvalidParam('is_watched', 'is_watched must be a valid value (0, 1).');
+                }
+
+                // Insert a new record
+                Db::query("INSERT INTO cache_list_watches (cache_list_id, user_id, is_watched) VALUES (LAST_INSERT_ID(), '$user_id', $isWatched)");
+            }
+
+            $result = array(
+                'success' => true,
+                'message' => 'Cache list created successfully.',
+                'list_id' => $listId
+            );
+        }
+        return Okapi::formatted_response($request, $result);
+    }
+}
+
diff --git a/okapi/services/lists/create/docs.xml b/okapi/services/lists/create/docs.xml
new file mode 100644
index 00000000..f8d9fd05
--- /dev/null
+++ b/okapi/services/lists/create/docs.xml
@@ -0,0 +1,46 @@
+<xml>
+    <brief>Create Cache List</brief>
+    <issue-id>627</issue-id>
+    <desc>
+        <p>This method creates a list for adding geocaches to. Only the list is created,
+        no geocaches are added to it during the create. For adding and removing geocaches
+        to/from the list use specific methods within the ::services/lists namespace
+        </p>
+    </desc>
+    <req name="list_name">
+    <p>A string, defining the human readable name of the list</p>
+    </req>
+    <opt name="list_description">
+        <p>A string via which a description of the list's purpose and
+        potentially content can be defined.</p>
+    </opt>
+    <opt name="list_status">
+        <p>This parameter can take the following values:
+        <ul>
+            <li><b>0</b> - The list is private</li>
+            <li><b>2</b> - The list is public</li>
+            <li><b>3</b> - The list is public and is visible in cache listings</li>
+        </ul>
+        </p>
+    </opt>
+    <opt name="list_password">
+        <p>This parameter allows to add a password to a private list. The password
+        has no meaning if the list is public. The first 16 alphanumeric characters
+        are used as a password. No encryption is performed in the password, instead
+        it is stored in the database in plain text.</p>
+        </opt>
+    <opt name="list_watch">
+        <p>A boolean, either 0, 1, false, true. If set to 1 or true
+        a user wants to get a notification if the content of the list
+        changes.</p>
+        </opt>
+    <common-format-params/>
+    <returns>
+        <p>A dictionary of the following structure:</p>
+        <ul>
+            <li>success - true</li>
+            <li>message - Cache list created successfully</li>
+            <li>list_id - The id of the list by which it can be referenced</li>
+        </ul>
+    </returns>
+</xml>
diff --git a/okapi/services/lists/delete/WebService.php b/okapi/services/lists/delete/WebService.php
new file mode 100644
index 00000000..89dd1ea8
--- /dev/null
+++ b/okapi/services/lists/delete/WebService.php
@@ -0,0 +1,57 @@
+<?php
+
+namespace okapi\services\lists\delete;
+
+use okapi\core\Db;
+use okapi\core\Okapi;
+use okapi\core\Request\OkapiRequest;
+use okapi\Settings;
+use okapi\core\Exception\InvalidParam;
+
+class WebService
+{
+
+    public static function options()
+    {
+        return array(
+            'min_auth_level' => 3
+        );
+    }
+
+    public static function call(OkapiRequest $request)
+    {
+        $result = array(
+            'success' => false
+        );
+
+        if (Settings::get('OC_BRANCH') == 'oc.de')
+        {
+            $user_id = $request->token->user_id;
+
+            $listId = $request->get_parameter('list_id');
+
+            if (empty($listId) || !is_numeric($listId)) {
+                throw new InvalidParam('list_id', 'list_id is mandatory and must be numeric.');
+            }
+
+            // Check if the list exists
+            $countQuery = Db::query("SELECT COUNT(*) AS count FROM cache_lists WHERE id = '$listId' AND user_id = '$user_id'");
+            $listExists = Db::fetch_assoc($countQuery)['count'];
+            if ($listExists == 0) {
+                throw new InvalidParam('list_id', 'The specified list does not exist.');
+            }
+
+            // Proceed with the deletion process
+            Db::query("DELETE FROM cache_lists WHERE id = '$listId'");
+            Db::query("DELETE FROM cache_list_watches WHERE cache_list_id = '$listId'");
+            Db::query("DELETE FROM cache_list_items WHERE cache_list_id   = '$listId'");
+
+            $result = array(
+                'success' => true,
+                'message' => 'Cache list deleted successfully.'
+            );
+        }
+        return Okapi::formatted_response($request, $result);
+    }
+}
+
diff --git a/okapi/services/lists/delete/docs.xml b/okapi/services/lists/delete/docs.xml
new file mode 100644
index 00000000..f6d218cc
--- /dev/null
+++ b/okapi/services/lists/delete/docs.xml
@@ -0,0 +1,20 @@
+<xml>
+    <brief>Delete Cache List</brief>
+    <issue-id>627</issue-id>
+    <desc>
+        <p>This method is used to delete a geocache list. The geocache objects
+        that were on the list will not be touched in any way.</p>
+    </desc>
+    <req name="list_id">
+        <p>The id of the list to be removed. IDs can be obtained by
+         the service ::services/lists/query</p>
+        </req>
+    <common-format-params/>
+    <returns>
+        <p>A dictionary of the following structure:</p>
+        <ul>
+            <li>success - true</li>
+            <li>message - cache list deleted successfully</li>
+        </ul>
+    </returns>
+</xml>
diff --git a/okapi/services/lists/get_caches/WebService.php b/okapi/services/lists/get_caches/WebService.php
new file mode 100644
index 00000000..b5e6e751
--- /dev/null
+++ b/okapi/services/lists/get_caches/WebService.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace okapi\services\lists\get_caches;
+
+use okapi\core\Db;
+use okapi\core\Okapi;
+use okapi\core\Request\OkapiRequest;
+use okapi\Settings;
+use okapi\core\Exception\InvalidParam;
+
+class WebService
+{
+    public static function options()
+    {
+        return array(
+            'min_auth_level' => 3
+        );
+    }
+
+    public static function call(OkapiRequest $request)
+    {
+        $result = array(
+            'success' => false
+        );
+
+        $user_id = $request->token->user_id;
+        $listId = $request->get_parameter('list_id');
+
+        if (empty($listId)) {
+            throw new InvalidParam('list_id', 'list_id is mandatory and must not be empty.');
+        }
+
+        // Fetch cache_ids associated with the specified list
+        $cacheIdsArray = Db::select_column("
+            SELECT cache_id
+            FROM cache_list_items
+            WHERE cache_list_id = '$listId'
+        ");
+
+        $cacheCount = count($cacheIdsArray);
+
+        // Fetch cache_codes based on cache_ids
+        $cacheCodesArray = array();
+
+        if (!empty($cacheIdsArray)) {
+            $cacheIds = implode(',', $cacheIdsArray);
+            $cacheCodesArray = Db::select_column(
+                "SELECT wp_oc FROM caches WHERE cache_id IN ($cacheIds)"
+            );
+        }
+
+        $result = array(
+            'success' => true,
+            'cache_codes' => implode('|', $cacheCodesArray),
+            'cache_count' => $cacheCount
+        );
+
+        return Okapi::formatted_response($request, $result);
+    }
+}
+
diff --git a/okapi/services/lists/get_caches/docs.xml b/okapi/services/lists/get_caches/docs.xml
new file mode 100644
index 00000000..c6885d8a
--- /dev/null
+++ b/okapi/services/lists/get_caches/docs.xml
@@ -0,0 +1,19 @@
+<xml>
+    <brief>Get Caches On A List</brief>
+    <issue-id>627</issue-id>
+    <desc>
+        <p>This method is used to get the geocache codes for the caches that are on the list.</p>
+    </desc>
+    <req name="list_id">
+        <p>The id of a list. List IDs can be obtained by ::service/lists/query</p>
+    </req>
+    <common-format-params/>
+    <returns>
+        <p>A dictionary of the following structure:</p>
+        <ul>
+            <li>success - true</li>
+            <li>cache_codes - A pipe separated string of cache_codes that are on the list</li>
+            <li>cache_count - the number of geocaches on the list</li>
+        </ul>
+    </returns>
+</xml>
diff --git a/okapi/services/lists/query/WebService.php b/okapi/services/lists/query/WebService.php
new file mode 100644
index 00000000..f0f3e490
--- /dev/null
+++ b/okapi/services/lists/query/WebService.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace okapi\services\lists\query;
+
+use okapi\core\Exception\InvalidParam;
+use okapi\core\Exception\ParamMissing;
+use okapi\core\Db;
+use okapi\core\Okapi;
+use okapi\core\OkapiServiceRunner;
+use okapi\core\Request\OkapiInternalRequest;
+use okapi\core\Request\OkapiRequest;
+use okapi\services\logs\LogsCommon;
+use okapi\Settings;
+
+class WebService
+{
+    public static function options()
+    {
+        return array(
+            'min_auth_level' => 3
+        );
+    }
+
+    public static function call(OkapiRequest $request)
+    {
+        $result = array(
+            'success' => false   // if the installation doesn't support it
+        );
+
+        if (Settings::get('OC_BRANCH') == 'oc.de')
+        {
+            $user_id = $request->token->user_id;
+            $rs = Db::query("
+                SELECT
+                    id,
+                    name,
+                    date_created,
+                    last_modified,
+                    last_added,
+                    description,
+                    is_public,
+                    (
+                        SELECT COUNT(*)
+                        FROM cache_list_items
+                        WHERE cache_list_id = cache_lists.id
+                    ) AS caches_count,
+                    (
+                        SELECT COUNT(*)
+                        FROM cache_list_watches
+                        WHERE cache_list_id = cache_lists.id
+                    ) AS watches_count
+                FROM cache_lists
+                WHERE user_id = '".Db::escape_string($user_id)."'
+            ");
+
+            $lists = [];
+            while ($list = Db::fetch_assoc($rs))
+            {
+                $lists[] = $list;
+            }
+
+            $result = json_encode($lists, JSON_PRETTY_PRINT);
+        }
+        return Okapi::formatted_response($request, $result);
+    }
+
+
+    // ------------------------------------------------------------------
+
+}
diff --git a/okapi/services/lists/query/docs.xml b/okapi/services/lists/query/docs.xml
new file mode 100644
index 00000000..8c3d0c71
--- /dev/null
+++ b/okapi/services/lists/query/docs.xml
@@ -0,0 +1,40 @@
+<xml>
+    <brief>Query Cache Lists</brief>
+    <issue-id>627</issue-id>
+    <desc>
+        <p>This method is used to query the metadata of all user owned cache lists.
+        Such a query ist typically performed by a client application that wants to render
+        a list of geocache lists at the UI. The metadata of the list is necessary and sufficient
+        for this purpose. Please note, an <i>id</i> is also part of the returned meta data.
+        Using this id as a reference code, specific operations can be performed on selected lists
+        for instance adding geocaches to the list, removing them, updating the metadata of the
+        referenced list or deleting the referenced list entirely. Typically such entities as
+        geocaches, logs, or lists, are referenced by a <i>referenceCode</i>, for instance
+        for geocaches, there would be a <i>cache_code</i> in the namespace <i>OCxxxxx</i> where
+        cache_code would be interpreted as a <i>referenceCode</i> for geocaches. Unfortunately lists
+        do not yet have such a <i>referenceCode</i>. They can be referenced only by their internal id,
+        which is named <i>id</i> in the returned objects for this method. This id is used as the
+        <i>list_id</i> parameter in all subsequent methods dealing with lists.
+        </p>
+    </desc>
+    <common-format-params/>
+    <returns>
+        <p>An array of the following structure:</p>
+        <pre>
+[
+    {
+        "id": 13,
+        "name": "This is my list",
+        "date_created": "2023-11-28 09:29:34",
+        "last_modified": "2023-11-28 09:49:16",
+        "last_added": "2023-11-28 09:40:18",
+        "description": "Just a list for testing",
+        "is_public": 0,
+        "caches_count": 4,
+        "watches_count": 1
+    },
+    { .... }
+]
+        </pre>
+    </returns>
+</xml>
diff --git a/okapi/services/lists/remove_caches/WebService.php b/okapi/services/lists/remove_caches/WebService.php
new file mode 100644
index 00000000..1ff393c4
--- /dev/null
+++ b/okapi/services/lists/remove_caches/WebService.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace okapi\services\lists\remove_caches;
+
+use okapi\core\Exception\InvalidParam;
+use okapi\core\Exception\ParamMissing;
+use okapi\core\Db;
+use okapi\core\Okapi;
+use okapi\core\OkapiServiceRunner;
+use okapi\core\Request\OkapiInternalRequest;
+use okapi\core\Request\OkapiRequest;
+use okapi\services\logs\LogsCommon;
+use okapi\Settings;
+
+class WebService
+{   
+    public static function options()
+    {
+        return array(
+            'min_auth_level' => 3
+        );
+    }
+
+    public static function call(OkapiRequest $request)
+    {   
+        $result = array( 
+            'success' => false
+        );
+        
+        $user_id = $request->token->user_id;
+
+        $listId     = $request->get_parameter('list_id');
+        $cacheCodes = $request->get_parameter('cache_codes');
+        
+        if (empty($listId)) {
+            throw new InvalidParam('list_id', 'list_id is mandatory and must not be empty.');
+        }
+        
+        if (empty($cacheCodes)) {
+            throw new InvalidParam('cache_codes', 'cache_codes is mandatory and must not be empty.');
+        }
+        
+        $cacheCodesArray = array_unique(explode('|', $cacheCodes));
+        
+        // Check the length
+        if (count($cacheCodesArray) > 500) {
+            throw new InvalidParam('cache_codes', 'The number of cache codes exceeds the limit of 500.');
+        }
+
+        // Escape cache codes and build the SQL query
+        $escapedCacheCodes = implode("','", array_map('\okapi\core\Db::escape_string', $cacheCodesArray));
+        
+        // Delete cache_ids from the cache_list_items table
+        $rs = Db::query("
+            DELETE FROM cache_list_items
+            WHERE cache_list_id = '$listId'
+              AND cache_id IN (
+                SELECT cache_id
+                FROM caches
+                WHERE wp_oc IN ('$escapedCacheCodes')
+              )
+        ");
+        
+        $removedCount = $rs->rowCount(); // Get the number of affected rows
+        
+        $result = array( 
+            'success'       => true,
+            'removed_count' => $removedCount
+        );
+
+        return Okapi::formatted_response($request, $result);
+    }
+}
+
diff --git a/okapi/services/lists/remove_caches/docs.xml b/okapi/services/lists/remove_caches/docs.xml
new file mode 100644
index 00000000..bbb1de4c
--- /dev/null
+++ b/okapi/services/lists/remove_caches/docs.xml
@@ -0,0 +1,23 @@
+<xml>
+    <brief>Remove Caches From List</brief>
+    <issue-id>627</issue-id>
+    <desc>
+        <p>This method removes geocaches from a list.</p>
+    </desc>
+    <req name="list_id">
+        <p>The id of a list. List IDs can be obtained by ::service/lists/query</p>
+    </req>
+    <req name="cache_codes">
+        <p>A pipe separated list of cache_codes to be removed to the list.</p>
+        <p>Up to 500 geoaches can be removed from the list by one request to
+        this method</p>
+    </req>
+    <common-format-params/>
+    <returns>
+        <p>A dictionary of the following structure:</p>
+        <ul>
+            <li>success - true</li>
+            <li>removed_count - number of geocaches removed from the list</li>
+        </ul>
+    </returns>
+</xml>
diff --git a/okapi/services/lists/update/WebService.php b/okapi/services/lists/update/WebService.php
new file mode 100644
index 00000000..0330abcb
--- /dev/null
+++ b/okapi/services/lists/update/WebService.php
@@ -0,0 +1,117 @@
+<?php
+
+namespace okapi\services\lists\update;
+
+use okapi\core\Exception\InvalidParam;
+use okapi\core\Db;
+use okapi\core\Okapi;
+use okapi\core\OkapiServiceRunner;
+use okapi\core\Request\OkapiRequest;
+use okapi\Settings;
+
+class WebService
+{
+
+    public static function options()
+    {
+        return array(
+            'min_auth_level' => 3
+        );
+    }
+
+    public static function call(OkapiRequest $request)
+    {
+        $result = array(
+            'success' => false
+        );
+
+        if (Settings::get('OC_BRANCH') == 'oc.de')
+        {
+            $user_id = $request->token->user_id;
+
+            $listId          = $request->get_parameter('list_id');
+            $listName        = $request->get_parameter('list_name');
+            $listDescription = $request->get_parameter('list_description');
+            $listStatus      = $request->get_parameter('list_status');
+            $listWatch       = $request->get_parameter('list_watch');
+            $listPassword    = $request->get_parameter('list_password');
+
+            if (empty($listId) || !is_numeric($listId)) {
+                throw new InvalidParam('list_id', 'list_id is mandatory and must be numeric.');
+            }
+
+            if (empty($listName) && empty($listDescription) && ($listStatus === null || $listStatus === '') && ($listWatch === null || $listWatch === '') && ($listPassword === null || $listPassword === '')) {
+                throw new InvalidParam('list_name, list_description, list_status, list_watch, list_password', 'At least one optional parameter is required.');
+            }
+
+            $updateFields = array();
+
+            if (!empty($listName)) {
+                $updateFields['name'] = Db::escape_string($listName);
+            }
+
+            if (!empty($listDescription)) {
+                $updateFields['description'] = Db::escape_string($listDescription);
+            }
+
+            if ($listStatus !== null && $listStatus !== '') {
+                $listStatus = (int)$listStatus;
+                if (!in_array($listStatus, [0, 2, 3])) {
+                    throw new InvalidParam('list_status', 'list_status must be a valid value (0, 2, 3).');
+                }
+                $updateFields['is_public'] = $listStatus;
+
+                // Handle list_password only if list_status is 0 (private)
+                if ($listStatus == 0) {
+                    if (isset($listPassword) && $listPassword !== '') {
+                        $updateFields['password'] = substr(Db::escape_string($listPassword), 0, 16);
+                    } else {
+                        $updateFields['password'] = null; // Remove the password
+                    }
+                }
+            }
+
+            if ($listWatch !== null && $listWatch !== '') {
+                $listWatch = (int)$listWatch;
+                $currentWatchState = (int) Db::query("
+                    SELECT COUNT(*)
+                    FROM cache_list_watches
+                    WHERE cache_list_id = '" . Db::escape_string($listId) . "'
+                    AND user_id = '" . Db::escape_string($user_id) . "'
+                ")->fetchColumn();
+
+                if ($listWatch == 1 && $currentWatchState == 0) {
+                    // Watched and not in cache_list_watches, insert
+                    Db::query("
+                        INSERT INTO cache_list_watches (cache_list_id, user_id)
+                        VALUES ('" . Db::escape_string($listId) . "', '" . Db::escape_string($user_id) . "')
+                    ");
+                } elseif ($listWatch == 0 && $currentWatchState > 0) {
+                    // Unwatched and in cache_list_watches, delete
+                    Db::query("
+                        DELETE FROM cache_list_watches
+                        WHERE cache_list_id = '" . Db::escape_string($listId) . "'
+                        AND user_id = '" . Db::escape_string($user_id) . "'
+                    ");
+                }
+            }
+
+            if (!empty($updateFields)) {
+                $updateQuery = "UPDATE cache_lists SET ";
+                $updateQuery .= implode(', ', array_map(function ($field, $value) {
+                    return "$field = '$value'";
+                }, array_keys($updateFields), $updateFields));
+                $updateQuery .= " WHERE id = '" . Db::escape_string($listId) . "'";
+
+                Db::query($updateQuery);
+            }
+
+            $result = array(
+                'success' => true,
+                'message' => 'Cache list updated successfully.'
+            );
+        }
+        return Okapi::formatted_response($request, $result);
+    }
+}
+
diff --git a/okapi/services/lists/update/docs.xml b/okapi/services/lists/update/docs.xml
new file mode 100644
index 00000000..34c1e10e
--- /dev/null
+++ b/okapi/services/lists/update/docs.xml
@@ -0,0 +1,50 @@
+<xml>
+    <brief>Update Cache List</brief>
+    <issue-id>627</issue-id>
+    <desc>
+        <p>This method is is used to update the meta data of an existing cache list.</p>
+    </desc>
+    <req name="list_id">
+        <p>The <i>list_id</i> uniquely references the
+        list for which the metadata should be updated. The <i>list_id</i> can be obtained
+        by <b>::services/lists/query</b></p>
+    </req>
+    <opt name="list_name">
+        <p>The new name of the list. The current name can be obtained by
+        <b>::services/lists/query</b></p>
+    </opt>
+    <opt name="list_description">
+        <p>The new description of the list. The current description can be obtained by
+        <b>::services/lists/query</b></p>
+    </opt>
+    <opt name="list_status">
+        <p>The new status of the list. The current status can be obtained by
+        <b>::services/lists/query</b></p>
+        <p>Status is defined as follows:
+        <ul>
+            <li>0  - indicates a private list</li>
+            <li>2  - indicates a public list</li>
+            <li>3  - indicates a public list, visible for all users in cache listings</li>
+          </ul>
+        </p>
+    </opt>
+    <opt name="list_password">
+        <p>The password for the list. Passwords only have a meaning if the list status is set to
+        private. The parameter is silently ignored otherwise. If the list is private, the first
+        16 alphanumeric charactes are taken as a password. No encryption is performed on the
+        password, instead it is stored as plain text in the database.</p>
+    </opt>
+    <opt name="list_watch">
+        <p>A boolean, either 0, 1, false, true. If set to 1 or true
+        a user wants to get a notification if the content of the list
+        changes.</p>
+        </opt>
+    <common-format-params/>
+    <returns>
+        <p>A dictionary of the following structure:</p>
+        <ul>
+            <li>success - true</li>
+            <li>message - Cache list updated sucessfully</li>
+        </ul>
+    </returns>
+</xml>