--- a/doc/hgrc.5.txt
+++ b/doc/hgrc.5.txt
@@ -145,20 +145,71 @@ hooks::
     incoming.email = /my/email/hook
     incoming.autobuild = /my/build/hook
 
+  Most hooks are run with environment variables set that give added
+  useful information.  For each hook below, the environment variables
+  it is passed are listed with names of the form "$HG_foo".
+
   changegroup;;
-    Run after a changegroup has been added via push or pull. Passed
-    the ID of the first new changeset in $NODE.
+    Run after a changegroup has been added via push, pull or
+    unbundle. ID of the first new changeset is in $HG_NODE.
   commit;;
     Run after a changeset has been created in the local repository.
-    Passed the ID of the newly created changeset in environment
-    variable $NODE.
+    ID of the newly created changeset is in $HG_NODE.  Parent
+    changeset IDs are in $HG_PARENT1 and $HG_PARENT2.
   incoming;;
     Run after a changeset has been pulled, pushed, or unbundled into
-    the local repository.  Passed the ID of the newly arrived
-    changeset in environment variable $NODE.
+    the local repository.  The ID of the newly arrived changeset is in
+    $HG_NODE.
+  outgoing;;
+    Run after sending changes from local repository to another.  ID of
+    first changeset sent is in $HG_NODE.  Source of operation is in
+    $HG_SOURCE; see "preoutgoing" hook for description.
+  prechangegroup;;
+    Run before a changegroup is added via push, pull or unbundle.
+    Exit status 0 allows the changegroup to proceed.  Non-zero status
+    will cause the push, pull or unbundle to fail.
   precommit;;
-    Run before starting a commit.  Exit status 0 allows the commit to
-    proceed.  Non-zero status will cause the commit to fail.
+    Run before starting a local commit.  Exit status 0 allows the
+    commit to proceed.  Non-zero status will cause the commit to fail.
+    Parent changeset IDs are in $HG_PARENT1 and $HG_PARENT2.
+  preoutgoing;;
+    Run before computing changes to send from the local repository to
+    another.  Non-zero status will cause failure.  This lets you
+    prevent pull over http or ssh.  Also prevents against local pull,
+    push (outbound) or bundle commands, but not effective, since you
+    can just copy files instead then.  Source of operation is in
+    $HG_SOURCE.  If "serve", operation is happening on behalf of
+    remote ssh or http repository.  If "push", "pull" or "bundle",
+    operation is happening on behalf of repository on same system.
+  pretag;;
+    Run before creating a tag.  Exit status 0 allows the tag to be
+    created.  Non-zero status will cause the tag to fail.  ID of
+    changeset to tag is in $HG_NODE.  Name of tag is in $HG_TAG.  Tag
+    is local if $HG_LOCAL=1, in repo if $HG_LOCAL=0.
+  pretxnchangegroup;;
+    Run after a changegroup has been added via push, pull or unbundle,
+    but before the transaction has been committed.  Changegroup is
+    visible to hook program.  This lets you validate incoming changes
+    before accepting them.  Passed the ID of the first new changeset
+    in $HG_NODE.  Exit status 0 allows the transaction to commit.
+    Non-zero status will cause the transaction to be rolled back and
+    the push, pull or unbundle will fail.
+  pretxncommit;;
+    Run after a changeset has been created but the transaction not yet
+    committed.  Changeset is visible to hook program.  This lets you
+    validate commit message and changes.  Exit status 0 allows the
+    commit to proceed.  Non-zero status will cause the transaction to
+    be rolled back.  ID of changeset is in $HG_NODE.  Parent changeset
+    IDs are in $HG_PARENT1 and $HG_PARENT2.
+  tag;;
+    Run after a tag is created.  ID of tagged changeset is in
+    $HG_NODE.  Name of tag is in $HG_TAG.  Tag is local if
+    $HG_LOCAL=1, in repo if $HG_LOCAL=0.
+
+  In earlier releases, the names of hook environment variables did not
+  have a "HG_" prefix.  These unprefixed names are still provided in
+  the environment for backwards compatibility, but their use is
+  deprecated, and they will be removed in a future release.
 
 http_proxy::
   Used to access web-based Mercurial repositories through a HTTP