diff --git a/changelogs/application_service/newsfragments/1810.clarification b/changelogs/application_service/newsfragments/1810.clarification
new file mode 100644
index 00000000..66dab495
--- /dev/null
+++ b/changelogs/application_service/newsfragments/1810.clarification
@@ -0,0 +1 @@
+Clarify that appservices should be notified of events relating to the sender_localpart user.
diff --git a/changelogs/internal/newsfragments/1814.clarification b/changelogs/internal/newsfragments/1814.clarification
new file mode 100644
index 00000000..a540ea7e
--- /dev/null
+++ b/changelogs/internal/newsfragments/1814.clarification
@@ -0,0 +1 @@
+Add support for rendering string formats.
diff --git a/changelogs/server_server/newsfragments/1818.clarification b/changelogs/server_server/newsfragments/1818.clarification
new file mode 100644
index 00000000..8c50b6ac
--- /dev/null
+++ b/changelogs/server_server/newsfragments/1818.clarification
@@ -0,0 +1 @@
+Clarify that whitespace around commas is allowed in the `X-Matrix` `Authorization` header value params list.
\ No newline at end of file
diff --git a/content/server-server-api.md b/content/server-server-api.md
index fb1b06f4..e92d871c 100644
--- a/content/server-server-api.md
+++ b/content/server-server-api.md
@@ -350,9 +350,10 @@ def authorization_headers(origin_name, origin_signing_key,
 
 The format of the Authorization header is given in
 [RFC 7235](https://datatracker.ietf.org/doc/html/rfc7235#section-2.1). In
-summary, the header begins with authorization scheme `X-Matrix`, followed by
-one or more spaces, followed by a comma-separated list of parameters written as
-name=value pairs. The names are case insensitive and order does not matter. The
+summary, the header begins with authorization scheme `X-Matrix`, followed by one
+or more spaces, followed by a comma-separated list of parameters written as
+name=value pairs. Zero or more spaces and tabs around each comma are allowed.
+The names are case insensitive and order does not matter. The
 values must be enclosed in quotes if they contain characters that are not
 allowed in `token`s, as defined in
 [RFC 7230](https://datatracker.ietf.org/doc/html/rfc7230#section-3.2.6); if a
@@ -363,8 +364,9 @@ replaced by the character that follows the backslash.
 
 For compatibility with older servers, the sender should
 - only include one space after `X-Matrix`,
-- only use lower-case names, and
-- avoid using backslashes in parameter values.
+- only use lower-case names,
+- avoid using backslashes in parameter values, and
+- avoid including whitespace around the commas between name=value pairs.
 
 For compatibility with older servers, the recipient should allow colons to be
 included in values without requiring the value to be enclosed in quotes.
diff --git a/data/api/application-service/definitions/registration.yaml b/data/api/application-service/definitions/registration.yaml
index d9dfe748..2d65a32c 100644
--- a/data/api/application-service/definitions/registration.yaml
+++ b/data/api/application-service/definitions/registration.yaml
@@ -29,7 +29,9 @@ properties:
     description: A secret token that the homeserver will use authenticate requests to the application service.
   sender_localpart:
     type: string
-    description: The localpart of the user associated with the application service.
+    description: |-
+      The localpart of the user associated with the application service. Events will be sent to the AS if this user is the target of the event, or
+      is a joined member of the room where the event occurred.
   namespaces:
     type: object
     title: Namespaces
@@ -40,9 +42,10 @@ properties:
           - $ref: namespace_list.yaml
           - description: |-
               A list of namespaces defining the user IDs that the application
-              service is interested in. Events will be sent to the AS if a
-              local user matching one of the namespaces is the target of the event,
-              or is a joined member of the room where the event occurred.
+              service is interested in, in addition to its `sender_localpart`.
+              Events will be sent to the AS if a local user matching one of the
+              namespaces is the target of the event, or is a joined member of
+              the room where the event occurred.
       rooms:
         allOf:
           - $ref: namespace_list.yaml
diff --git a/data/custom-formats.yaml b/data/custom-formats.yaml
index f0001c80..5da7e6ab 100644
--- a/data/custom-formats.yaml
+++ b/data/custom-formats.yaml
@@ -31,3 +31,8 @@ mx-event-id:
   title: Event ID
   url: /appendices#event-ids
   # regex: "^\\$"
+
+uri:
+  title: URI
+  url: http://tools.ietf.org/html/rfc3986
+  # no regex
diff --git a/layouts/partials/openapi/render-object-table.html b/layouts/partials/openapi/render-object-table.html
index 72ea5a8a..d2b09acb 100644
--- a/layouts/partials/openapi/render-object-table.html
+++ b/layouts/partials/openapi/render-object-table.html
@@ -128,6 +128,8 @@ resolve-additional-types.)
 
     * `anchor`: optional HTML element id for the target type, which will be used to link to it.
 
+    * `format`: optional string for the format of the type, used for strings.
+
 */}}
 {{ define "partials/property-type" }}
     {{ $type := "" }}
@@ -143,6 +145,15 @@ resolve-additional-types.)
         {{ $items := .items }}
         {{ $inner_type := partial "property-type" $items }}
         {{ $type = delimit (slice "[" $inner_type "]") "" }}
+    {{ else if eq .type "string" }}
+        {{ $type = "string" }}
+
+        {{/* If the string uses a known format, use it. */}}
+        {{ with .format }}
+            {{ with partial "custom-format" . }}
+                {{ $type = . }}
+            {{ end }}
+        {{ end }}
     {{ else if or (reflect.IsSlice .type) .oneOf }}
         {{/*
             It's legal to specify an array of types.
@@ -167,7 +178,7 @@ resolve-additional-types.)
 
         {{ $type = delimit $types "|" }}
     {{ else }}
-        {{/* A simple type like string or boolean */}}
+        {{/* A simple type like integer or boolean */}}
         {{ $type = (htmlEscape .type) }}
     {{ end }}
 
@@ -241,8 +252,8 @@ resolve-additional-types.)
         {{ range $formatId, $formatType := $formatMap.Values }}
             {{ $formatKey := "string" }}
             {{ if ne $formatId "string" }}
-                {{ with index site.Data "custom-formats" $formatId }}
-                    {{ $formatKey = printf "<a href=\"%s\">%s</a>" (htmlEscape .url) (htmlEscape .title) }}
+                {{ with partial "custom-format" $formatId }}
+                    {{ $formatKey = . }}
                 {{ else }}
                     {{ errorf "Unsupported value for `x-pattern-format`: %s" $formatId }}
                 {{ end }}
@@ -290,3 +301,18 @@ resolve-additional-types.)
     {{ if (index .property "x-addedInMatrixVersion") }}{{ partial "added-in" (dict "v" (index .property "x-addedInMatrixVersion")) }}{{ end -}}
     {{ if (index .property "x-changedInMatrixVersion") }}{{ partial "changed-in" (dict "changes_dict" (index .property "x-changedInMatrixVersion")) }}{{ end -}}
 {{ end }}
+
+
+{{/*
+    Computes the type to display for a string format, given the identifier of
+    the format as a string.
+*/}} 
+{{ define "partials/custom-format" }}
+  {{ $customFormat := "" }}
+
+  {{ with index site.Data "custom-formats" . }}
+    {{ $customFormat = printf "<a href=\"%s\">%s</a>" (htmlEscape .url) (htmlEscape .title) }}
+  {{ end }}
+
+  {{ return $customFormat }}
+{{ end }}