feat(logging/logback): add logging docs regarding SLF4J Fluent Logging API

cmtjk · cmtjk · commit d34d4de1448d · 2026-02-22T11:20:16.000+01:00
diff --git a/docs/core/logging.md b/docs/core/logging.md
@@ -378,6 +378,10 @@ You can use Powertools for AWS Lambda Logging with either the `@Logging` annotat
     }
     ```
 
+???+ warning "SLF4J Fluent Logging API"
+    When using [SLF4J Fluent Logging API](https://www.slf4j.org/manual.html#fluent) **do not add reserved keys** listed in [standard structured keys](#standard-structured-keys) and [additional structured keys](#additional-structured-keys) as key-value pairs via `addKeyValue`.
+    This may cause unindented behavior.
+
 ## Standard structured keys
 
 Your logs will always include the following keys in your structured logging:

Original file line number	Diff line number	Diff line change
@@ -378,6 +378,10 @@ You can use Powertools for AWS Lambda Logging with either the `@Logging` annotat
`378`	`378`	`}`
`379`	`379`	```
`380`	`380`
	`381`	`+???+ warning "SLF4J Fluent Logging API"`
	`382`	+ When using [SLF4J Fluent Logging API](https://www.slf4j.org/manual.html#fluent) do not add reserved keys listed in [standard structured keys](#standard-structured-keys) and [additional structured keys](#additional-structured-keys) as key-value pairs via `addKeyValue`.
	`383`	`+ This may cause unindented behavior.`
	`384`	`+`
`381`	`385`	`## Standard structured keys`
`382`	`386`
`383`	`387`	`Your logs will always include the following keys in your structured logging:`