Define how SDK implements Logger.Enabled (#4381)

CHANGELOG.md

@@ -15,6 +15,9 @@ release.
 
 ### Logs
 
+- Define how SDK implements `Logger.Enabled`.
+  ([#4381](https://github.com/open-telemetry/opentelemetry-specification/pull/4381))
+
 ### Baggage
 
 ### Resource

specification/logs/noop.md

@@ -4,7 +4,7 @@ linkTitle: No-Op
 
 # Logs API No-Op Implementation
 
-**Status**: [Stable](../document-status.md)
+**Status**: [Stable](../document-status.md), except where otherwise specified
 
 <details>
 <summary> Table of Contents </summary>
@@ -15,6 +15,7 @@ linkTitle: No-Op
   * [Logger Creation](#logger-creation)
 - [Logger](#logger)
   * [Emit LogRecord](#emit-logrecord)
+  * [Enabled](#enabled)
 
 <!-- tocstop -->
 
@@ -55,3 +56,9 @@ return the same `Logger` instances to all creation requests.
 
 The No-Op `Logger` MUST allow
 for [emitting LogRecords](./api.md#emit-a-logrecord).
+
+### Enabled
+
+**Status**: [Development](../document-status.md)
+
+MUST always return `false`.

specification/logs/sdk.md

@@ -16,6 +16,7 @@
   * [ForceFlush](#forceflush)
 - [Logger](#logger)
   * [LoggerConfig](#loggerconfig)
+  * [Enabled](#enabled)
 - [Additional LogRecord interfaces](#additional-logrecord-interfaces)
   * [ReadableLogRecord](#readablelogrecord)
   * [ReadWriteLogRecord](#readwritelogrecord)
@@ -190,6 +191,18 @@ It consists of the following parameters:
   necessary for implementations to ensure that changes to `disabled` are
   immediately visible to callers of `Enabled`.
 
+### Enabled
+
+**Status**: [Development](../document-status.md)
+
+`Enabled` MUST return `false` when:
+
+- there are no registered [`LogRecordProcessors`](#logrecordprocessor),
+- `Logger` is disabled ([`LoggerConfig.disabled`](#loggerconfig) is `true`).
+
+Otherwise, it SHOULD return `true`.
+It MAY return `false` to support additional optimizations and features.
+
 ## Additional LogRecord interfaces
 
 In this document we refer to `ReadableLogRecord` and `ReadWriteLogRecord`, defined as follows.