diff --git a/docs/static/processing-info.asciidoc b/docs/static/processing-info.asciidoc
index 6466c9af0..fe9904109 100644
--- a/docs/static/processing-info.asciidoc
+++ b/docs/static/processing-info.asciidoc
@@ -44,3 +44,5 @@ processing cost required to preserve order.
 The Java pipeline initialization time appears in the startup logs at INFO level.
 Initialization time is the time it takes to compile the pipeline config and
 instantiate the compiled execution for all workers.
+
+include::reserved-fields.asciidoc[]
diff --git a/docs/static/reserved-fields.asciidoc b/docs/static/reserved-fields.asciidoc
new file mode 100644
index 000000000..d05fe9b73
--- /dev/null
+++ b/docs/static/reserved-fields.asciidoc
@@ -0,0 +1,39 @@
+[float]
+[[reserved-fields]] 
+==== Reserved fields in {ls} events 
+
+Some fields in {ls} events are reserved, or are required to adhere to a certain
+shape. Using these fields can cause runtime exceptions when the event API or
+plugins encounter incompatible values.
+
+[cols="<,<",options="header",]
+|=======================================================================
+| | 
+| <<metadata,`@metadata`>> |A key/value map. 
+
+Ruby-based Plugin API: value is an 
+https://javadoc.io/static/org.jruby/jruby-core/9.2.5.0/org/jruby/RubyHash.html[org.jruby.RubyHash]. 
+
+Java-based Plugin API: value is an 
+https://github.com/elastic/logstash/blob/master/logstash-core/src/main/java/org/logstash/ConvertedMap.java[org.logstash.ConvertedMap].
+ 
+In serialized form (such as JSON): a key/value map where the keys must be
+strings and the values are not constrained to a particular type.
+
+| `@timestamp` |An object holding representation of a specific moment in time.
+
+Ruby-based Plugin API: value is an
+https://javadoc.io/static/org.jruby/jruby-core/9.2.5.0/org/jruby/RubyTime.html[org.jruby.RubyTime].
+
+Java-based Plugin API: value is a
+https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/time/Instant.html[java.time.Instant].
+
+In serialized form (such as JSON) or when setting with Event#set: an
+ISO8601-compliant String value is acceptable.
+
+| `@version` |A string, holding an integer value.
+| `tags` |An array of distinct strings
+|=======================================================================
+
+
+