diff --git a/INSTALL b/INSTALL
index c43b77e..acc6641 100644
--- a/INSTALL
+++ b/INSTALL
@@ -53,10 +53,10 @@ Add /opt/pgc-www/local-override.yml containing e.g.
    email-address: webmaster@example.net?Subject=Love your site!
    email-name: webmaster@example.net
 
-Likewise, you can place your own favicon.ico into public/.
-
-After you restart the app, your address should appear on the 'about' page
-and your favicon should appear instead of Mojolicious's.
+After you restart the app, your address should appear on the 'about'
+page.  You can likewise place your own favicon.ico and robots.txt into
+public/.  Entries for these are present in the supplied .gitignore so
+will be safe on updates.
 
 5. Configure systemd to run the app under fastcgi, via socket activation.
 
@@ -65,7 +65,6 @@ Suggested unit files follow, to go into /etc/systemd/system.
 = pgc.socket ================================
 [Unit]
 Description = PG Catalog socket
-PartOf = pgc.service
 
 [Socket]
 Accept = false
@@ -132,12 +131,12 @@ Run
 
    # systemctl daemon-reload
    # systemctl start pgc.socket
-   
+
 You can apply resource limits by running
 
    # systemctl set-property pgc.socket \
       IPAddressAllow=localhost IPAddressDeny=any
-   
+
    # systemctl set-property pgc.service \
       CPUQuota=50% CPUWeight=50 MemoryHigh=128M MemoryMax=256M
 
@@ -151,5 +150,13 @@ Enable the service to start on boot.
 
 I use lighttpd and followed the guidance in
 <https://github.com/mojolicious/mojo/wiki/Deploying-on-Lighttpd-with-FastCGI>.
+However, I disabled HTTP2 with
+
+   server.feature-flags = ("server.h2proto" => "disable")
+
+because of sporadic trouble when using Firefox.  Sometimes FF
+apparently fails to send the correct GET to follow a link, instead
+sending only a PRI.  Possibly an instance of
+<https://redmine.lighttpd.net/boards/2/topics/10682>.
 
 Comments and questions are welcome at <barnold@tilde.club>.