address review comments

CHANGELOG.md

@@ -6,10 +6,32 @@ breaking changes in the upcoming 3.x release. This release is scheduled for
 
 ## v2.27.0 - TBD
 
-* We have stopped testing on CentOS 7, Debian 10 (Buster), and RockyLinux 8 as
+- We have stopped testing on CentOS 7, Debian 10 (Buster), and RockyLinux 8 as
   these distros are EOL or in some form of "security only" support period.
   Note that we used CentOS 7 as a proxy for testing RedHat Enterprise Linux 7.
 
+### [OpenTelemetry](/google/cloud/opentelemetry/README.md)
+
+#### Bazel
+
+The `--io_opentelemetry_cpp//api:with_abseil` flag was marked as deprecated in
+OpenTelemetry v1.16.0. It may be removed in future versions.
+
+In previous versions of `opentelemetry-cpp`, this flag was required for
+compatibility with Abseil. It is no longer necessary, as `opentelemetry-cpp` is
+compiled with Abseil by default.
+
+We have stopped using the flag to validate Bazel build configurations with
+OpenTelemetry tracing enabled.
+
+If you are building `google-cloud-cpp` with `opentelemetry-cpp` < v1.16.0, you
+will need to supply the flag for compatibility with Abseil. The following can be
+added to your `.bazelrc` file.
+
+```bash
+build --@io_opentelemetry_cpp//api:with_abseil
+```
+
 ## v2.26.0 - 2024-07
 
 ### BREAKING TESTING CHANGES

doc/packaging.md

@@ -126,9 +126,9 @@ quickstart guides also cover this use-case.
 `google-cloud-cpp` also has an **optional** dependency on the following
 libraries:
 
-| Library                           | Minimum version | Description                |
-| --------------------------------- | --------------- | -------------------------- |
-| [OpenTelemetry][opentelemetry-gh] | 1.9.1           | An observability framework |
+| Library                           | Minimum version | Description                    |
+| --------------------------------- | --------------- | ------------------------------ |
+| [OpenTelemetry][opentelemetry-gh] | 1.9.1           | An observability framework[^7] |
 
 Note that these libraries may also depend on other libraries. The following
 instructions include steps to install these indirect dependencies too.
@@ -1531,6 +1531,9 @@ cmake --build cmake-out --target install
     workaround conflicts between system pre-processor macros and symbols used in
     the Protobuf-generated code.
 
+[^7]: See the [OpenTelemetry quickstart][otel-qs] for detailed instructions on how
+    to enable and build this optional dependency.
+
 [abseil-gh]: https://github.com/abseil/abseil-cpp
 [abseil/abseil-cpp#696]: https://github.com/abseil/abseil-cpp/issues/696
 [crc32c-gh]: https://github.com/google/crc32c
@@ -1543,6 +1546,7 @@ cmake --build cmake-out --target install
 [nlohmann-json-gh]: https://github.com/nlohmann/json
 [openssl-gh]: https://github.com/openssl/openssl
 [opentelemetry-gh]: https://github.com/open-telemetry/opentelemetry-cpp
+[otel-qs]: https://github.com/googleapis/google-cloud-cpp/tree/main/google/cloud/opentelemetry/quickstart#opentelemetry-dependency
 [protobuf-gh]: https://github.com/protocolbuffers/protobuf
 [spanner-link]: https://github.com/googleapis/google-cloud-cpp/tree/main/google/cloud/spanner#readme
 [storage-link]: https://github.com/googleapis/google-cloud-cpp/tree/main/google/cloud/storage#readme