diff --git a/SHARING.md b/SHARING.md
index 6fd52791..1bf7df0b 100644
--- a/SHARING.md
+++ b/SHARING.md
@@ -526,6 +526,8 @@ Execute delete+create in case `PathOrToken` needs to be changed.
 
  * Output: text/plain|application/json
 
+ * Level-2 entries in "Actions" can be deleted using special value `#DEL#` (see API example below related to "bday" conversion)
+
  * Examples:
 
 ###### form->text
@@ -738,3 +740,79 @@ BEGIN:VCALENDAR
 ...
 END:VCALENDAR
 ```
+
+##### Adjusting templates per share
+
+```bash
+## set specific config: conversion_bday_summary_template
+curl -u owner:$ownerpw -H "Content-Type: application/json" -d '{ "PathMapped": "/owner/addressbook/", "PathOrToken": "/owner/bday-of-addressbook/", "Actions": { "config": { "conversion_bday_summary_template": "{fn} ({year}" }}}' http://localhost:5232/.sharing/v1/map/update
+{"ApiVersion": 1, "Status": "success"}
+```
+
+```bash
+## list adjusted share
+curl -s -H "Content-Type: application/json" -u owner:$ownerpw -d '{ "PathMapped": "/owner/addressbook/", "PathOrToken": "/owner/bday-of-addressbook/"}' http://localhost:5232/.sharing/v1/map/list | jq
+{
+  "ApiVersion": 1,
+  "Lines": 1,
+  "Status": "success",
+  "Content": [
+    {
+      "ShareType": "map",
+      "PathOrToken": "/owner/bday-of-addressbook/",
+      "PathMapped": "/owner/addressbook/",
+      "Conversion": "bday",
+      "Owner": "owner",
+      "User": "owner",
+      "Permissions": "r",
+      "EnabledByOwner": true,
+      "EnabledByUser": true,
+      "HiddenByOwner": false,
+      "HiddenByUser": false,
+      "TimestampCreated": 1774339430,
+      "TimestampUpdated": 1780240328,
+      "Properties": {},
+      "Actions": {
+        "config": {
+          "conversion_bday_summary_template": "{fn} ({year}"
+        }
+      }
+    }
+  ]
+}
+```
+
+```bash
+## delete specific config: conversion_bday_summary_template (using special value "#DEL#")
+curl -u owner:$ownerpw -H "Content-Type: application/json" -d '{ "PathMapped": "/owner/addressbook/", "PathOrToken": "/owner/bday-of-addressbook/", "Actions": { "config": { "conversion_bday_summary_template": "#DEL#" }}}' http://localhost:5232/.sharing/v1/map/update
+{"ApiVersion": 1, "Status": "success"}
+```
+
+```bash
+## list share (specific config is deleted)
+curl -s -H "Content-Type: application/json" -u owner:$ownerpw -d '{ "PathMapped": "/owner/addressbook/", "PathOrToken": "/owner/bday-of-addressbook/"}' http://localhost:5232/.sharing/v1/map/list | jq
+{
+  "ApiVersion": 1,
+  "Lines": 1,
+  "Status": "success",
+  "Content": [
+    {
+      "ShareType": "map",
+      "PathOrToken": "/owner/bday-of-addressbook/",
+      "PathMapped": "/owner/addressbook/",
+      "Conversion": "bday",
+      "Owner": "owner",
+      "User": "owner",
+      "Permissions": "r",
+      "EnabledByOwner": true,
+      "EnabledByUser": true,
+      "HiddenByOwner": false,
+      "HiddenByUser": false,
+      "TimestampCreated": 1774339430,
+      "TimestampUpdated": 1780240558,
+      "Properties": {},
+      "Actions": {}
+    }
+  ]
+}
+```
diff --git a/radicale/sharing/__init__.py b/radicale/sharing/__init__.py
index bee138b0..340f97e5 100644
--- a/radicale/sharing/__init__.py
+++ b/radicale/sharing/__init__.py
@@ -128,6 +128,7 @@ SHARING_BDAY_AGE_MAX_DEFAULT: int = 99
 SHARING_BDAY_SUMMARY_TEMPLATE_DEFAULT: str = "[{n:f} {n:g}|{fn}|{nickname}] ({year}) (BDAY)"
 SHARING_BDAY_DESCRIPTION_TEMPLATE_DEFAULT: str = "BDAY={year}-{month}-{day}"
 SHARING_BDAY_CATEGORIES_DEFAULT: str = 'Birthday'
+SHARING_ACTIONS_DELETE_VALUE: str = '#DEL#'
 
 
 def check_bday_max_age(data: Any) -> int:
@@ -555,7 +556,6 @@ class BaseSharing:
 
     # adjust a share
     def sharing_collection_update(self, ShareType: str, PathOrToken: str, OwnerOrUser: str, Properties: dict) -> None:
-        """ returning dict with PathMapped, Owner, Permissions or None if not found"""
         logger.info("sharing/collection/update: ShareType=%r PathOrToken=%r OwnerOrUser=%r", ShareType, PathOrToken, OwnerOrUser)
         # Filter properies for permitted ones
         properties_filtered: dict = {}
@@ -943,7 +943,7 @@ class BaseSharing:
                 if level1 in ACTIONS_WHITELIST:
                     for level2 in request_data['Actions'][level1]:
                         if level2 in ACTIONS_WHITELIST[level1]:
-                            if callable(ACTIONS_WHITELIST[level1][level2]):
+                            if callable(ACTIONS_WHITELIST[level1][level2]) and request_data['Actions'][level1][level2] != SHARING_ACTIONS_DELETE_VALUE:
                                 try:
                                     value = ACTIONS_WHITELIST[level1][level2](request_data['Actions'][level1][level2])
                                 except ValueError:
@@ -1253,6 +1253,32 @@ class BaseSharing:
                             logger.trace("" + api_info + ": clear property %r", prop)
                             del Properties[prop]
 
+            if 'Actions' in request_data:
+                if Actions is None:
+                    # clear actions
+                    Actions = {}
+                elif Actions == {}:
+                    # empty, nothing to do
+                    pass
+                elif share['Actions'] is not None:
+                    # replace properties
+                    for level1 in share['Actions']:
+                        if level1 not in Actions:
+                            Actions[level1] = {}  # initialize level1
+                        for level2 in share['Actions'][level1]:
+                            logger.trace("" + api_info + ": check for existing Actions entry %r->%r", level1, level2)
+                            if level2 not in Actions[level1]:
+                                logger.trace("" + api_info + ": overtake Actions entry %r->%r", level1, level2)
+                                Actions[level1][level2] = share['Actions'][level1][level2]
+                            elif Actions[level1][level2] == SHARING_ACTIONS_DELETE_VALUE:
+                                # unset, do nothing
+                                logger.trace("" + api_info + ": delete Actions entry %r->%r", level1, level2)
+                                del Actions[level1][level2]
+                        if len(Actions[level1]) == 0:
+                            logger.trace("" + api_info + ": delete Actions entry %r", level1)
+                            # unset level1
+                            del Actions[level1]
+
             if Permissions is not None and share['Conversion'] is not None:
                 Permissions = str(Permissions)
                 if share['Conversion'] == "bday":
diff --git a/radicale/tests/test_sharing.py b/radicale/tests/test_sharing.py
index 3d08ab67..521a3858 100644
--- a/radicale/tests/test_sharing.py
+++ b/radicale/tests/test_sharing.py
@@ -5199,6 +5199,115 @@ permissions: RrWw""")
                 }}
             _, headers, answer = self._sharing_api_json("map", "update", check=400, login="owner:ownerpw", json_dict=json_dict)
 
+            self.configure({
+                "sharing": {"conversion_bday_description_template": sharing.SHARING_BDAY_DESCRIPTION_TEMPLATE_DEFAULT,
+                            "conversion_bday_alarm_trigger_template": "",
+                            }
+                })
+
+            # update template
+            logging.info("\n*** update map(bday) user/owner:r with valid description template -> 200")
+            json_dict = {}
+            json_dict['User'] = "user"
+            json_dict['PathMapped'] = path_mapped
+            json_dict['PathOrToken'] = path_shared_r
+            json_dict['Actions'] = {"config": {
+                "conversion_bday_summary_template": "{fn} ({year})",
+                "conversion_bday_description_template": "Birthday={year}-{month}-{day}"
+                }}
+            _, headers, answer = self._sharing_api_json("map", "update", check=200, login="owner:ownerpw", json_dict=json_dict)
+
+            logging.info("\n*** GET collection user format: description -> ok")
+            _, headers, answer = self.request("GET", path_shared_3, login="user:userpw")
+            assert "DESCRIPTION:Birthday=1990-01-01" in answer
+            assert "SUMMARY:Test-FN-C3 (1990)" in answer
+
+            # update template
+            logging.info("\n*** update map(bday) user/owner:r with valid empty description template -> 200")
+            json_dict = {}
+            json_dict['User'] = "user"
+            json_dict['PathMapped'] = path_mapped
+            json_dict['PathOrToken'] = path_shared_r
+            json_dict['Actions'] = {"config": {
+                "conversion_bday_description_template": ""
+                }}
+            _, headers, answer = self._sharing_api_json("map", "update", check=200, login="owner:ownerpw", json_dict=json_dict)
+
+            logging.info("\n*** GET collection user format: description -> ok")
+            _, headers, answer = self.request("GET", path_shared_3, login="user:userpw")
+            assert "DESCRIPTION:Birthday=" not in answer
+            assert "DESCRIPTION:BDAY=" not in answer
+            assert "SUMMARY:Test-FN-C3 (1990)" in answer
+
+            # update template
+            logging.info("\n*** update map(bday) user/owner:r DEL description template -> 200")
+            json_dict = {}
+            json_dict['User'] = "user"
+            json_dict['PathMapped'] = path_mapped
+            json_dict['PathOrToken'] = path_shared_r
+            json_dict['Actions'] = {"config": {
+                "conversion_bday_description_template": sharing.SHARING_ACTIONS_DELETE_VALUE
+                }}
+            _, headers, answer = self._sharing_api_json("map", "update", check=200, login="owner:ownerpw", json_dict=json_dict)
+
+            logging.info("\n*** GET collection user format: description -> ok")
+            _, headers, answer = self.request("GET", path_shared_3, login="user:userpw")
+            assert "DESCRIPTION:Birthday=" not in answer
+            assert "DESCRIPTION:BDAY=" in answer
+            assert "SUMMARY:Test-FN-C3 (1990)" in answer
+
+            # update template
+            logging.info("\n*** update map(bday) user/owner:r DEL summary template -> 200")
+            json_dict = {}
+            json_dict['User'] = "user"
+            json_dict['PathMapped'] = path_mapped
+            json_dict['PathOrToken'] = path_shared_r
+            json_dict['Actions'] = {"config": {
+                "conversion_bday_summary_template": sharing.SHARING_ACTIONS_DELETE_VALUE
+                }}
+            _, headers, answer = self._sharing_api_json("map", "update", check=200, login="owner:ownerpw", json_dict=json_dict)
+
+            logging.info("\n*** GET collection user format: description -> ok")
+            _, headers, answer = self.request("GET", path_shared_3, login="user:userpw")
+            assert "DESCRIPTION:Birthday=" not in answer
+            assert "DESCRIPTION:BDAY=" in answer
+            assert "SUMMARY:Family3Test Given3Test !n:a! (Birthday)" in answer
+
+            # update template
+            logging.info("\n*** update map(bday) user/owner:r with valid age max -> 200")
+            json_dict = {}
+            json_dict['User'] = "user"
+            json_dict['PathMapped'] = path_mapped
+            json_dict['PathOrToken'] = path_shared_r
+            json_dict['Actions'] = {"config": {
+                "conversion_bday_age_max": 5,
+                "conversion_bday_summary_template": "{fn} ({year}/{age})",
+                }}
+            _, headers, answer = self._sharing_api_json("map", "update", check=200, login="owner:ownerpw", json_dict=json_dict)
+
+            logging.info("\n*** GET collection user format: summary with age -> ok")
+            _, headers, answer = self.request("GET", path_shared_3, login="user:userpw")
+            assert "Test-FN-C3 (1990/0)" in answer
+            assert "Test-FN-C3 (1990/5)" in answer
+            assert "Test-FN-C3 (1990/6)" not in answer
+
+            # update template
+            logging.info("\n*** update map(bday) user/owner:r with valid age max -> 200")
+            json_dict = {}
+            json_dict['User'] = "user"
+            json_dict['PathMapped'] = path_mapped
+            json_dict['PathOrToken'] = path_shared_r
+            json_dict['Actions'] = {"config": {
+                "conversion_bday_age_max": sharing.SHARING_ACTIONS_DELETE_VALUE
+                }}
+            _, headers, answer = self._sharing_api_json("map", "update", check=200, login="owner:ownerpw", json_dict=json_dict)
+
+            logging.info("\n*** GET collection user format: summary with age -> ok")
+            _, headers, answer = self.request("GET", path_shared_3, login="user:userpw")
+            assert "Test-FN-C3 (1990/0)" in answer
+            assert "Test-FN-C3 (1990/5)" in answer
+            assert "Test-FN-C3 (1990/6)" in answer
+
     def test_sharing_api_map_vcf_bday_age_template(self) -> None:
         """share-by-map with conversion=bday template tests with age."""
         self.configure({"auth": {"type": "htpasswd",