[1.10.x] Documented how allow_migrate() interacts with makemigrations.

Backport of df92f6f2e3ad2c6b1e4da7f4225d313e2640d30f from master

1 files changed, 6 insertions, 4 deletions

diff --git a/docs/topics/db/multi-db.txt b/docs/topics/db/multi-db.txt
index b685d3c53e..a60b637ba3 100644
--- a/docs/topics/db/multi-db.txt
+++ b/docs/topics/db/multi-db.txt
@@ -183,10 +183,12 @@ A database Router is a class that provides up to four methods:
     This method can also be used to determine the availability of a model on a
     given database.
 
-    Note that migrations will just silently not perform any operations on a
-    model for which this returns ``False``. This may result in broken foreign
-    keys, extra tables, or missing tables if you change it once you have
-    applied some migrations.
+    :djadmin:`makemigrations` always creates migrations for model changes, but
+    if ``allow_migrate()`` returns ``False``, any migration operations for the
+    ``model_name`` will be silently skipped when running :djadmin:`migrate` on
+    the ``db``. Changing the behavior of ``allow_migrate()`` for models that
+    already have migrations may result in broken foreign keys, extra tables,
+    or missing tables.
 
 A router doesn't have to provide *all* these methods -- it may omit one
 or more of them. If one of the methods is omitted, Django will skip