Added note on order of meta and blog plugin

Author: squidfunk

docs/reference/index.md

@@ -24,9 +24,13 @@ tags. Add the following lines to `mkdocs.yml`:
 
 ``` yaml
 plugins:
-  - meta
+  - meta # (1)!
 ```
 
+1.  Note that the meta plugin should be located at the beginning of the list
+    of `plugins`, so that other plugins (including the [built-in blog plugin])
+    will pick up the set defaults.
+
 > If you need to be able to build your documentation with and without
 > [Insiders], please refer to the [built-in plugins] section to learn how
 > shared configurations help to achieve this.
@@ -48,6 +52,7 @@ The following configuration options are available:
     1.  Note that it's strongly recommended to prefix meta files with a `.`,
         since otherwise they would be included in the build output.
 
+  [built-in blog plugin]: ../setup/setting-up-a-blog.md#built-in-blog-plugin
   [built-in plugins]: ../insiders/getting-started.md#built-in-plugins
 
 ## Usage

docs/setup/setting-up-a-blog.md

@@ -1165,6 +1165,16 @@ authors, and add a `.meta.yml` file to set common properties:
       - World
     ```
 
+Note that order matters – the [built-in meta plugin] must be defined before the
+blog plugin in `mkdocs.yml`, so that all set defaults are correctly picked up
+by the [built-in blog plugin]:
+
+``` yaml
+plugins:
+  - meta
+  - blog
+```
+
 Lists and dictionaries in `.meta.yml` files are merged and deduplicated with the
 values defined for a post, which means you can define common properties in
 `.meta.yml` and then add specific properties or overrides for each post.