diff --git a/src/feature/dirauth/feature_dirauth.dox b/src/feature/dirauth/feature_dirauth.dox
index 93c680e472bb16bed2775b2852fe155a416dbae5..9ee2d0458973f80a5b46bc19621b7e652a6923f6 100644
--- a/src/feature/dirauth/feature_dirauth.dox
+++ b/src/feature/dirauth/feature_dirauth.dox
@@ -3,4 +3,9 @@
 @brief feature/dirauth: Directory authority implementation.
 
 This module handles running Tor as a directory authority.
+
+The directory protocol is specified in
+[dir-spec.txt](https://gitweb.torproject.org/torspec.git/tree/dir-spec.txt).
+
+
 **/
diff --git a/src/feature/hs/feature_hs.dox b/src/feature/hs/feature_hs.dox
index 35a574d015a95698b5b7cfb33daac32d2acf6330..32f44d57fb0cc00c3e8b2f7dae1f36ccb096368f 100644
--- a/src/feature/hs/feature_hs.dox
+++ b/src/feature/hs/feature_hs.dox
@@ -2,4 +2,9 @@
 @dir /feature/hs
 @brief feature/hs: v3 (current) onion service protocol
 
+This directory implements the v3 onion service protocol,
+as specified in
+[rend-spec-v3.txt](https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt).
+
+
 **/
diff --git a/src/feature/rend/feature_rend.dox b/src/feature/rend/feature_rend.dox
index e92406804d812a1f4644552260841bcbb134ad12..ed0784521c46b0041b0194afe55ae9fad251c19d 100644
--- a/src/feature/rend/feature_rend.dox
+++ b/src/feature/rend/feature_rend.dox
@@ -2,4 +2,8 @@
 @dir /feature/rend
 @brief feature/rend: version 2 (old) hidden services
 
+This directory implements the v2 onion service protocol,
+as specified in
+[rend-spec-v2.txt](https://gitweb.torproject.org/torspec.git/tree/rend-spec-v2.txt).
+
 **/
diff --git a/src/mainpage.dox b/src/mainpage.dox
index 7c64e0dffb7646bdf8f6230d7f157461faaf44fd..02ce8675e702b5471ae589c276e36acc58fae143 100644
--- a/src/mainpage.dox
+++ b/src/mainpage.dox
@@ -1,9 +1,7 @@
 /**
 @mainpage Tor source reference
 
-@section intro Getting to know Tor
-
-Welcome!
+@section intro Welcome to Tor
 
 This documentation describes the general structure of the Tor codebase, how
 it fits together, what functionality is available for extending Tor, and
@@ -22,7 +20,9 @@ This document is not an overview of the Tor protocol.  For that, see the
 design paper and the specifications at https://spec.torproject.org/ .
 
 For more information about Tor's coding standards and some helpful
-development tools, see doc/HACKING in the Tor repository.
+development tools, see
+[doc/HACKING](https://gitweb.torproject.org/tor.git/tree/doc/HACKING) in the
+Tor repository.
 
 @section highlevel The very high level