diff --git a/netbpfload/netbpfload.33rc b/netbpfload/netbpfload.33rc
index 05f566e..ca2b288 100644
--- a/netbpfload/netbpfload.33rc
+++ b/netbpfload/netbpfload.33rc
@@ -1,3 +1,15 @@
+# This file takes effect only on T and U (on V netbpfload.35rc takes priority).
+#
+# The service is started from netd's libnetd_updatable shared library
+# on initial (boot time) startup of netd.
+#
+# However we never start this service on U QPR3.
+#
+# This is due to lack of a need: U QPR2 split the previously single
+# platform bpfloader into platform netbpfload -> platform bpfloader.
+# U QPR3 made the platform netbpfload unconditionally exec apex netbpfload,
+# so by the time U QPR3's netd runs, apex netbpfload is already done.
+
 service mdnsd_netbpfload /apex/com.android.tethering/bin/netbpfload
     capabilities CHOWN SYS_ADMIN NET_ADMIN
     group system root graphics network_stack net_admin net_bw_acct net_bw_stats net_raw
diff --git a/netd/BpfHandler.cpp b/netd/BpfHandler.cpp
index 6cdf97b..f08ac44 100644
--- a/netd/BpfHandler.cpp
+++ b/netd/BpfHandler.cpp
@@ -171,7 +171,10 @@
     }
 
     if (false && !mainlineNetBpfLoadDone()) {
-        // we're on < U QPR3 & it's the first time netd is starting up (unless crashlooping)
+        // We're on < U QPR3 & it's the first time netd is starting up (unless crashlooping)
+        //
+        // On U QPR3+ netbpfload is guaranteed to run before the platform bpfloader,
+        // so waitForProgsLoaded() implies mainlineNetBpfLoadDone().
         if (!base::SetProperty("ctl.start", "mdnsd_netbpfload")) {
             ALOGE("Failed to set property ctl.start=mdnsd_netbpfload, see dmesg for reason.");
             abort();