Add the {size} template variable to the network-icon spec.

Author: sadiepowell

extensions/network-icon.md

@@ -7,6 +7,10 @@ copyrights:
     name: "Simon Ser"
     period: "2025"
     email: "contact@emersion.fr"
+  -
+    name: "Sadie Powell"
+    period: "2026"
+    email: "sadie@witchery.services"
 ---
 
 ## Notes for implementing work-in-progress version
@@ -23,10 +27,20 @@ The `NETWORK` ISUPPORT token allows servers to advertise their network name. Thi
 
 ## The `draft/ICON` ISUPPORT token
 
-If a server publishes a `draft/ICON` ISUPPORT token, the value MUST be a URL to an image. The URL SHOULD use the "https" scheme.
+If a server publishes a `draft/ICON` ISUPPORT token, the value MUST be a URL to an image. This image SHOULD be square. The URL SHOULD use the "https" scheme.
+
+The URL MAY contain the `{size}` template variable that clients MUST replace with an integer to request a specific image size in pixels.  Clients MUST treat this template variable as a hint and MUST NOT assume that they will get the exact same size image back as requested.
 
 Servers MAY implement [extended-isupport](extended-isupport.html) to allow clients to fetch the network icon before connection registration.
 
-## Example
+## Examples
+
+This section is non-normative.
+
+Server using an SVG icon:
 
     S: :irc.example.org 005 * NETWORK=Example draft/ICON=https://example.org/icon.svg :are supported by this server
+
+Server using a PNG icon that can be scaled using the `{size}` template variable:
+
+    S: :irc.example.org 005 * NETWORK=Example draft/ICON=https://example.net/icon.png?size={size} :are supported by this server