diff --git a/docs/conf.py b/docs/conf.py
index 932be7b..461ed59 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -38,6 +38,7 @@ extensions = [
 ]
 
 intersphinx_mapping = {
+    'alembic': ('https://alembic.sqlalchemy.org/en/latest/', None),
     'rattail': ('https://rattailproject.org/docs/rattail/', None),
     'tailbone': ('https://rattailproject.org/docs/tailbone/', None),
     'wuttjamaican': ('https://rattailproject.org/docs/wuttjamaican/', None),
diff --git a/docs/data/db/extend.rst b/docs/data/db/extend.rst
index d956538..cdc7583 100644
--- a/docs/data/db/extend.rst
+++ b/docs/data/db/extend.rst
@@ -23,6 +23,8 @@ by the rattail-corepos package for extension tables it provides).
 First Alembic Version
 ---------------------
 
+(For more authoritative docs see :ref:`alembic:multiple_bases`.)
+
 In order to add custom extensions to the schema, you will need to establish
 some things for sake of Alembic.  Note that these steps are only required for
 the "first" extension you add; subsequent versions are somewhat simpler and are
@@ -45,28 +47,17 @@ custom location first, core rattail goes last.
    script_location = rattail.db:alembic
    version_locations = poser.db:alembic/versions rattail.db:alembic/versions
 
-Run a command like this (replacing names etc. as needed) to generate the script
-in your versions folder::
+Run a command like this (replacing names etc. as needed) to generate
+the script in your versions folder.  Please pay close attention and
+make sure you have all args correct::
 
    cd /srv/envs/poser
-   bin/alembic -c app/rattail.conf revision --autogenerate --head rattail@head --version-path ~/src/poser/poser/db/alembic/versions/ -m 'initial Poser tables'
+   bin/alembic -c app/rattail.conf revision --autogenerate --head base --branch-label=poser --version-path ~/src/poser/poser/db/alembic/versions/ -m 'initial Poser tables'
 
 If all goes well that command output should end by telling you where the new
 script lives.  You will want to review this of course, to make sure it includes
 all your new tables.
 
-But you must also declare this version as a new branch head.  This lets your
-custom versions have a life of their own, essentially.  So going forward, when
-you upgrade your DB schema, both the core Rattail tables, as well as your own,
-will be migrated properly.
-
-There are two variables near the top of the script which you must edit, like so:
-
-.. code-block:: python
-
-   down_revision = None
-   branch_labels = ('poser',)
-
 And with all that in place, you can apply the migration to your DB (this part
 is normal)::