Doc polishing.

Author: garyrussell

spring-kafka-docs/src/main/asciidoc/kafka.adoc

@@ -5737,7 +5737,7 @@ The reason for the two properties is because, while you might want to retain onl
 `appendOriginalHeaders` is applied to all headers named `*ORIGINAL*` while `stripPreviousExceptionHeaders` is applied to all headers named `*EXCEPTION*`.
 
 Starting with version 2.8.4, you now can control which of the standard headers will be added to the output record.
-See the `enum HeadersToAdd` for the names of the (currently) 10 standard headers that are added by default.
+See the `enum HeadersToAdd` for the generic names of the (currently) 10 standard headers that are added by default (these are not the actual header names, just an abstraction; the actual header names are set up by the `getHeaderNames()` method which subclasses can override.
 
 To exclude headers, use the `excludeHeaders()` method; for example, to suppress adding the exception stack trace in a header, use: