README.md in opentelemetry-exporter-otlp-0.18.0 vs README.md in opentelemetry-exporter-otlp-0.19.0

@@ -38,11 +38,11 @@
 # Configure the sdk with custom export
 OpenTelemetry::SDK.configure do |c|
   c.add_span_processor(
     OpenTelemetry::SDK::Trace::Export::BatchSpanProcessor.new(
       OpenTelemetry::Exporter::OTLP::Exporter.new(
-        endpoint: 'http://localhost:55680'
+        compression: 'gzip'
       )
     )
   )
 end
 
@@ -62,9 +62,25 @@
   end
 end
 ```
 
 For additional examples, see the [examples on github][examples-github].
+
+## How can I configure the OTLP exporter?
+
+The collector exporter can be configured explicitly in code, as shown above, or via environment variables. The configuration parameters, environment variables, and defaults are shown below.
+
+| Parameter           | Environment variable                         | Default                             |
+| ------------------- | -------------------------------------------- | ----------------------------------- |
+| `endpoint:`         | `OTEL_EXPORTER_OTLP_ENDPOINT`                | `"http://localhost:4317/v1/traces"` |
+| `certificate_file: `| `OTEL_EXPORTER_OTLP_CERTIFICATE`             |                                     |
+| `headers:`          | `OTEL_EXPORTER_OTLP_HEADERS`                 |                                     |
+| `compression:`      | `OTEL_EXPORTER_OTLP_COMPRESSION`             |                                     |
+| `timeout:`          | `OTEL_EXPORTER_OTLP_TIMEOUT`                 | `10`                                |
+| `ssl_verify_mode:`  | `OTEL_RUBY_EXPORTER_OTLP_SSL_VERIFY_PEER` or | `OpenSSL::SSL:VERIFY_PEER`          |
+|                     | `OTEL_RUBY_EXPORTER_OTLP_SSL_VERIFY_NONE`    |                                     |
+
+`ssl_verify_mode:` parameter values should be flags for server certificate verification: `OpenSSL::SSL:VERIFY_PEER` and `OpenSSL::SSL:VERIFY_NONE` are acceptable. These values can also be set using the appropriately named environment variables as shown where `VERIFY_PEER` will take precedence over `VERIFY_NONE`.  Please see [the Net::HTTP docs](https://ruby-doc.org/stdlib-2.5.1/libdoc/net/http/rdoc/Net/HTTP.html#verify_mode) for more information about these flags.
 
 ## How can I get involved?
 
 The `opentelemetry-exporter-otlp` gem source is [on github][repo-github], along with related gems including `opentelemetry-sdk`.