diff --git a/52.md b/52.md
index f35d9040..86e88be1 100644
--- a/52.md
+++ b/52.md
@@ -26,11 +26,15 @@ The `.content` of these events should be a detailed description of the calendar
 
 The list of tags are as follows:
 * `d` (required) universally unique identifier (UUID). Generated by the client creating the calendar event.
-* `title` (required) title of the calendar event
+* `type` (required) type of the event, list of [_onsite_, _online_]
 * `start` (required) inclusive start date in ISO 8601 format (YYYY-MM-DD). Must be less than `end`, if it exists.
 * `end` (optional) exclusive end date in ISO 8601 format (YYYY-MM-DD). If omitted, the calendar event ends on the same date as `start`.
-* `location` (optional, repeated) location of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call
+* `address` (required if `type` is _onsite_) address of the calendar event following ISO 19160:2015 and splitting the elements in the array; the country is specified in ISO 3166
+* `place` (optional, permitted only if `type` is _onsite_) name of the place of the calendar event. e.g. univeristy, building, business, public space
 * `g` (optional) [geohash](https://en.wikipedia.org/wiki/Geohash) to associate calendar event with a searchable physical location
+* `url` (required if `type` is _online_) the url where the user can access the calendar event; it can be a nostr:naddr1xxx or a http(s)://xxx endpoint
+* `languages` (optional) list
+  of [IETF language tags](https://en.wikipedia.org/wiki/IETF_language_tag) indicating the major languages used in the event
 * `p` (optional, repeated) 32-bytes hex pubkey of a participant, optional recommended relay URL, and participant's role in the meeting
 * `t` (optional, repeated) hashtag to categorize calendar event
 * `r` (optional, repeated) references / links to web pages, documents, video calls, recorded videos, etc.
@@ -48,6 +52,8 @@ The following tags are deprecated:
   "tags": [
     ["d", "<UUID>"],
 
+    ["type", "<onsite>", "<online>"],
+
     ["title", "<title of calendar event>"],
 
     // Dates
@@ -55,13 +61,18 @@ The following tags are deprecated:
     ["end", "<YYYY-MM-DD>"],
 
     // Location
-    ["location", "<location>"],
+    ["address", "<street name and number>", "<city or locality>", "<postal or zip code>", "<country>"],
+    ["place", "<place>"],
     ["g", "<geohash>"],
+    ["url", "<nostr:naddr1xxx or a http(s)://xxx>"],
 
     // Participants
     ["p", "<32-bytes hex of a pubkey>", "<optional recommended relay URL>", "<role>"],
     ["p", "<32-bytes hex of a pubkey>", "<optional recommended relay URL>", "<role>"],
 
+    // Languages
+    ["languages", "<lang>", "<lang>"]
+
     // Hashtags
     ["t", "<tag>"],
     ["t", "<tag>"],
@@ -85,13 +96,18 @@ The `.content` of these events should be a detailed description of the calendar
 
 The list of tags are as follows:
 * `d` (required) universally unique identifier (UUID). Generated by the client creating the calendar event.
+* `type` (required) type of the event, list of [_onsite_, _online_]
 * `title` (required) title of the calendar event
 * `start` (required) inclusive start Unix timestamp in seconds. Must be less than `end`, if it exists.
 * `end` (optional) exclusive end Unix timestamp in seconds. If omitted, the calendar event ends instantaneously.
 * `start_tzid` (optional) time zone of the start timestamp, as defined by the IANA Time Zone Database. e.g., `America/Costa_Rica`
 * `end_tzid` (optional) time zone of the end timestamp, as defined by the IANA Time Zone Database. e.g., `America/Costa_Rica`. If omitted and `start_tzid` is provided, the time zone of the end timestamp is the same as the start timestamp.
-* `location` (optional, repeated) location of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call
+* `address` (required if `type` is _onsite_) address of the calendar event following ISO 19160:2015 and splitting the elements in the array; the country is specified in ISO 3166
+* `place` (optional, permitted only if `type` is _onsite_) name of the place of the calendar event. e.g. univeristy, building, business, public space
 * `g` (optional) [geohash](https://en.wikipedia.org/wiki/Geohash) to associate calendar event with a searchable physical location
+* `url` (required if `type` is _online_) the url where the user can access the calendar event; it can be a nostr:naddr1xxx (preferably a NIP-53 event) or an http(s)://xxx endpoint
+* `languages` (optional) list
+  of [IETF language tags](https://en.wikipedia.org/wiki/IETF_language_tag) indicating the major languages used in the event
 * `p` (optional, repeated) 32-bytes hex pubkey of a participant, optional recommended relay URL, and participant's role in the meeting
 * `t` (optional, repeated) hashtag to categorize calendar event
 * `r` (optional, repeated) references / links to web pages, documents, video calls, recorded videos, etc.
@@ -109,6 +125,8 @@ The following tags are deprecated:
   "tags": [
     ["d", "<UUID>"],
 
+    ["type", "<onsite>", "<online>"],
+
     ["title", "<title of calendar event>"],
 
     // Timestamps
@@ -119,8 +137,13 @@ The following tags are deprecated:
     ["end_tzid", "<IANA Time Zone Database identifier>"],
 
     // Location
-    ["location", "<location>"],
+    ["address", "<street name and number>", "<city or locality>", "<postal or zip code>", "<country>"],
+    ["place", "<place>"],
     ["g", "<geohash>"],
+    ["url", "<nostr:naddr1xxx or a http(s)://xxx>"],
+
+    // Languages
+    ["languages", "<lang>", "<lang>"]
 
     // Participants
     ["p", "<32-bytes hex of a pubkey>", "<optional recommended relay URL>", "<role>"],