Clarify OTLP/HTTP endpoint configuration option handling

CHANGELOG.md

@@ -28,6 +28,8 @@ release.
 - Clarify that the configuration options MAY be implemented by the exporter,
   the SDK, or a separate component (e.g. environment-based autoconfiguration component).
   ([#3730](https://github.com/open-telemetry/opentelemetry-specification/pull/3730))
+- Clarify exporter's endpoints configuration options handling.
+  ([#3739](https://github.com/open-telemetry/opentelemetry-specification/pull/3739))
 
 ### Compatibility
 

specification/protocol/exporter.md

@@ -14,11 +14,20 @@ The following configuration options MUST be available to configure the OTLP expo
 The configuration options MAY be implemented directly in the OTLP exporter, in the SDK, or in a separate component (e.g. environment-based autoconfiguration component).
 Each configuration option MUST be overridable by a signal specific option.
 
-- **Endpoint (OTLP/HTTP)**: Target URL to which the exporter is going to send spans or metrics. The endpoint MUST be a valid URL with scheme (http or https) and host, MAY contain a port, SHOULD contain a path and MUST NOT contain other parts (such as query string or fragment). A scheme of https indicates a secure connection. When using `OTEL_EXPORTER_OTLP_ENDPOINT`, exporters MUST construct per-signal URLs as  [described below](#endpoint-urls-for-otlphttp). The per-signal endpoint configuration options take precedence and can be used to override this behavior (the URL is used as-is for them, without any modifications). See the [OTLP Specification][otlphttp-req] for more details.
+- **Endpoint (OTLP/HTTP)**: Target URL to which the exporter is going to send spans or metrics.
+  The option:
+  - MUST accept be a valid URL with scheme (`http` or `https`) and host,
+  - MUST accept an optional port,
+  - MUST accept an optional path,
+  - MAY not accept a query string,
+  - MAY not accept a fragment.
+
+  A scheme of `https` indicates a secure connection.
+  When using `OTEL_EXPORTER_OTLP_ENDPOINT`, exporters MUST construct per-signal URLs as [described below](#endpoint-urls-for-otlphttp). The per-signal endpoint configuration options take precedence and can be used to override this behavior (the URL is used as-is for them, without any modifications). See the [OTLP Specification][otlphttp-req] for more details.
   - Default:  `http://localhost:4318` [1]
   - Env vars: `OTEL_EXPORTER_OTLP_ENDPOINT` `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT` `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT` `OTEL_EXPORTER_OTLP_LOGS_ENDPOINT`
 
-- **Endpoint (OTLP/gRPC)**: Target to which the exporter is going to send spans or metrics. The endpoint SHOULD accept any form allowed by the underlying gRPC client implementation. Additionally, the endpoint MUST accept a URL with a scheme of either `http` or `https`. A scheme of `https` indicates a secure connection and takes precedence over the `insecure` configuration setting. A scheme of `http` indicates an insecure connection and takes precedence over the `insecure` configuration setting. If the gRPC client implementation does not support an endpoint with a scheme of `http` or `https` then the endpoint SHOULD be transformed to the most sensible format for that implementation.
+- **Endpoint (OTLP/gRPC)**: Target to which the exporter is going to send spans or metrics. The option SHOULD accept any form allowed by the underlying gRPC client implementation. Additionally, the option MUST accept a URL with a scheme of either `http` or `https`. A scheme of `https` indicates a secure connection and takes precedence over the `insecure` configuration setting. A scheme of `http` indicates an insecure connection and takes precedence over the `insecure` configuration setting. If the gRPC client implementation does not support an endpoint with a scheme of `http` or `https` then the endpoint SHOULD be transformed to the most sensible format for that implementation.
   - Default: `http://localhost:4317` [1]
   - Env vars: `OTEL_EXPORTER_OTLP_ENDPOINT` `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT` `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT` `OTEL_EXPORTER_OTLP_LOGS_ENDPOINT`