Fix what can be modified via ReadWriteLogRecord (open-telemetry#3907)

Fixes
open-telemetry#3902

## Changes

Fix what can be modified via `ReadWriteLogRecord`.

CHANGELOG.md

@@ -24,6 +24,8 @@ release.
   ([#3855](https://github.com/open-telemetry/opentelemetry-specification/pull/3855))
 - Clarify that `ReadableLogRecord` and `ReadWriteLogRecord` can be represented using a single type.
   ([#3898](https://github.com/open-telemetry/opentelemetry-specification/pull/3898))
+- Fix what can be modified via `ReadWriteLogRecord`.
+  ([#3907](https://github.com/open-telemetry/opentelemetry-specification/pull/3907))
 
 ### Events
 

specification/logs/sdk.md

@@ -154,11 +154,20 @@ and `ReadWriteLogRecord`.
 
 ### ReadWriteLogRecord
 
-A function receiving this as an argument MUST be able to write to the
-full [LogRecord](data-model.md#log-and-event-record-definition) and additionally MUST be able to retrieve all
-information
-that was added to the `LogRecord` (as with
-[ReadableLogRecord](#readablelogrecord)).
+ReadWriteLogRecord is a superset of [ReadableLogRecord](#readablelogrecord).
+
+A function receiving this as an argument MUST additionally be able to modify
+the following information added to the [LogRecord](data-model.md#log-and-event-record-definition):
+
+* [`Timestamp`](./data-model.md#field-timestamp)
+* [`ObservedTimestamp`](./data-model.md#field-observedtimestamp)
+* [`SeverityText`](./data-model.md#field-severitytext)
+* [`SeverityNumber`](./data-model.md#field-severitynumber)
+* [`Body`](./data-model.md#field-body)
+* [`Attributes`](./data-model.md#field-attributes) (addition, modification, removal)
+* [`TraceId`](./data-model.md#field-traceid)
+* [`SpanId`](./data-model.md#field-spanid)
+* [`TraceFlags`](./data-model.md#field-traceflags)
 
 ## LogRecord Limits