diff --git a/README.md b/README.md
index 4437196..1ed08f1 100644
--- a/README.md
+++ b/README.md
@@ -148,8 +148,11 @@ There is no PyPI package yet; the file is the distribution.
 {"application":"roam","name":"command","value":1.0,"tags":{"name":"home","version":"1.4.0"}}
 ```
 
-`value` is omitted when not given; `tags` always holds at least `version`, and
-`install` when the client has an [installation ID](#every-event-carries-a-random-installation-id). The server assigns the
+`value` is omitted when not given, and when it is NaN or infinite (JSON has no
+such numbers); `tags` always holds at least `version`, and
+`install` when the client has an [installation ID](#every-event-carries-a-random-installation-id). A tag whose
+key or value is `None` is left out, and every other key and value is sent as a
+string. An event with a blank `name` is not sent at all. The server assigns the
 timestamp. A `201` is success; anything else is logged at `DEBUG` and dropped.
 
 ## Keys
diff --git a/trace_client/trace_client.py b/trace_client/trace_client.py
index 3515ac2..6f08222 100644
--- a/trace_client/trace_client.py
+++ b/trace_client/trace_client.py
@@ -244,7 +244,9 @@ def enabled(self) -> bool:
     def report(self, name: str, value: Optional[float] = None,
                tags: Optional[Mapping[str, str]] = None) -> None:
         """Report that ``name`` happened, with an optional numeric value and
-        optional string tags. Returns immediately; see the class docstring."""
+        optional string tags. Returns immediately; see the class docstring.
+        A blank ``name`` sends nothing. A NaN or infinite ``value``, and any
+        tag whose key or value is ``None``, is left out of the event."""
         if self._queue is None:
             return
         try: