Explicit note on self references

Issue: SPR-14402

Author: jhoeller

src/asciidoc/core-beans.adoc

@@ -4634,13 +4634,28 @@ If you intend to express annotation-driven injection by name, do not primarily u
 `@Autowired`, even if is technically capable of referring to a bean name through
 `@Qualifier` values. Instead, use the JSR-250 `@Resource` annotation, which is
 semantically defined to identify a specific target component by its unique name, with
-the declared type being irrelevant for the matching process.
+the declared type being irrelevant for the matching process. `@Autowired` has rather
+different semantics: After selecting candidate beans by type, the specified String
+qualifier value will be considered within those type-selected candidates only, e.g.
+matching an "account" qualifier against beans marked with the same qualifier label.
 
 For beans that are themselves defined as a collection/map or array type, `@Resource`
 is a fine solution, referring to the specific collection or array bean by unique name.
 That said, as of 4.3, collection/map and array types can be matched through Spring's
 `@Autowired` type matching algorithm as well, as long as the element type information
 is preserved in `@Bean` return type signatures or collection inheritance hierarchies.
+In this case, qualifier values can be used to select among same-typed collections,
+as outlined in the previous paragraph.
+
+As of 4.3, `@Autowired` also considers self references for injection, i.e. references
+back to the bean that is currently injected. Note that self injection is a fallback;
+regular dependencies on other components always have precedence. In that sense, self
+references do not participate in regular candidate selection and are therefore in
+particular never primary; on the contrary, they always end up as lowest precedence.
+In practice, use self references as a last resort only, e.g. for calling other methods
+on the same instance through the bean's transactional proxy: Consider factoring out
+the affected methods to a separate delegate bean in such a scenario. Alternatively,
+use `@Resource` which may obtain a proxy back to the current bean by its unique name.
 
 `@Autowired` applies to fields, constructors, and multi-argument methods, allowing for
 narrowing through qualifier annotations at the parameter level. By contrast, `@Resource`