This change includes the following:

* Fixes spelling issue in Kotlin tutorial
* Removes the Common Types section from the overview topic (which is a duplicate of the section by the same name in the Protobuf Best Practices topic)
* Updates the organization of the Protouf Best Practices topic
* Softens some language in the Proto2 Language Guide
* Removes the Recommended Downcast Method topic from the public docs, since it applies only internally
* Removes some Proto1 content from the Java Proto Names topic, as well as adding some clarifying information to the other sections

PiperOrigin-RevId: 578258372
Change-Id: Ic318d1491b8270c09f2a465a9010fd95e94038aa

Author: Protocol Buffer Team

content/getting-started/kotlintutorial.md

@@ -199,7 +199,7 @@ existing APIs generated for protocol buffers for Java. This ensures that
 codebases written in a mix of Java and Kotlin can interact with the same
 protocol buffer message objects without any special handling or conversion.
 
-Protocol buffers for other Kotlin compilation targets, such as Javascript and
+Protocol buffers for other Kotlin compilation targets, such as JavaScript and
 native, are not currently supported.
 
 Compiling `addressbook.proto` gives you the following APIs in Java:

content/overview.md

@@ -278,36 +278,8 @@ Protocol buffers support many scalar value types, including integers that use
 both variable-length encoding and fixed sizes. You can also create your own
 composite data types by defining messages that are, themselves, data types that
 you can assign to a field. In addition to the simple and composite value types,
-several common types are published.
-
-### Common Types {#common-types}
-
-*   [`Duration`](https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/duration.proto)
-    is a signed, fixed-length span of time, such as 42s.
-*   [`Timestamp`](https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/timestamp.proto)
-    is a point in time independent of any time zone or calendar, such as
-    2017-01-15T01:30:15.01Z.
-*   [`Interval`](https://github.com/googleapis/googleapis/blob/master/google/type/interval.proto)
-    is a time interval independent of time zone or calendar, such as
-    2017-01-15T01:30:15.01Z - 2017-01-16T02:30:15.01Z.
-*   [`Date`](https://github.com/googleapis/googleapis/blob/master/google/type/date.proto)
-    is a whole calendar date, such as 2025-09-19.
-*   [`DayOfWeek`](https://github.com/googleapis/googleapis/blob/master/google/type/dayofweek.proto)
-    is a day of the week, such as Monday.
-*   [`TimeOfDay`](https://github.com/googleapis/googleapis/blob/master/google/type/timeofday.proto)
-    is a time of day, such as 10:42:23.
-*   [`LatLng`](https://github.com/googleapis/googleapis/blob/master/google/type/latlng.proto)
-    is a latitude/longitude pair, such as 37.386051 latitude and -122.083855
-    longitude.
-*   [`Money`](https://github.com/googleapis/googleapis/blob/master/google/type/money.proto)
-    is an amount of money with its currency type, such as 42 USD.
-*   [`PostalAddress`](https://github.com/googleapis/googleapis/blob/master/google/type/postal_address.proto)
-    is a postal address, such as 1600 Amphitheatre Parkway Mountain View, CA
-    94043 USA.
-*   [`Color`](https://github.com/googleapis/googleapis/blob/master/google/type/color.proto)
-    is a color in the RGBA color space.
-*   [`Month`](https://github.com/googleapis/googleapis/blob/master/google/type/month.proto)
-    is a month of the year, such as April.
+several [common types](/programming-guides/dos-donts#common)
+are published.
 
 ## History {#history}
 

content/programming-guides/dos-donts.md

@@ -19,6 +19,24 @@ one is using the field, don’t re-use a tag number. If the change was live ever
 there could be serialized versions of your proto in a log
 somewhere. Or there could be old code in another server that will break.
 
+<a id="do-reserve-tag-numbers-for-deleted-fields"></a>
+
+## **Do** Reserve Tag Numbers for Deleted Fields {#reserve-tag-numbers}
+
+When you delete a field that's no longer used, reserve its tag number so that no
+one accidentally re-uses it in the future. Just `reserved 2, 3;` is enough. No
+type required (lets you trim dependencies!). You can also reserve names to avoid
+recycling now-deleted field names: `reserved "foo", "bar";`.
+
+<a id="do-reserve-numbers-for-deleted-enum-values"></a>
+
+## **Do** Reserve Numbers for Deleted Enum Values {#reserve-deleted-numbers}
+
+When you delete an enum value that's no longer used, reserve its number so that
+no one accidentally re-uses it in the future. Just `reserved 2, 3;` is enough.
+You can also reserve names to avoid recycling now-deleted value names: `reserved
+"FOO", "BAR";`.
+
 <a id="dont-change-the-type-of-a-field"></a>
 
 ## **Don't** Change the Type of a Field {#change-type}
@@ -109,26 +127,31 @@ when a perfectly suitable common type already exists!
 
 ### Common Types {#common}
 
-*   [interval](https://github.com/googleapis/googleapis/blob/master/google/type/interval.proto)
+*   [`Duration`](https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/duration.proto)
+    is a signed, fixed-length span of time, such as 42s.
+*   [`Timestamp`](https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/timestamp.proto)
+    is a point in time independent of any time zone or calendar, such as
+    2017-01-15T01:30:15.01Z.
+*   [`interval`](https://github.com/googleapis/googleapis/blob/master/google/type/interval.proto)
     is a time interval independent of time zone or calendar (for example,
     2017-01-15T01:30:15.01Z - 2017-01-16T02:30:15.01Z).
-*   [date](https://github.com/googleapis/googleapis/blob/master/google/type/date.proto)
+*   [`date`](https://github.com/googleapis/googleapis/blob/master/google/type/date.proto)
     is a whole calendar date (for example, 2005-09-19).
-*   [dayofweek](https://github.com/googleapis/googleapis/blob/master/google/type/dayofweek.proto)
+*   [`dayofweek`](https://github.com/googleapis/googleapis/blob/master/google/type/dayofweek.proto)
     is a day of week (for example, Monday).
-*   [timeofday](https://github.com/googleapis/googleapis/blob/master/google/type/timeofday.proto)
+*   [`timeofday`](https://github.com/googleapis/googleapis/blob/master/google/type/timeofday.proto)
     is a time of day (for example, 10:42:23).
-*   [latlng](https://github.com/googleapis/googleapis/blob/master/google/type/latlng.proto)
+*   [`latlng`](https://github.com/googleapis/googleapis/blob/master/google/type/latlng.proto)
     is a latitude/longitude pair (for example, 37.386051 latitude and
     -122.083855 longitude).
-*   [money](https://github.com/googleapis/googleapis/blob/master/google/type/money.proto)
+*   [`money`](https://github.com/googleapis/googleapis/blob/master/google/type/money.proto)
     is an amount of money with its currency type (for example, 42 USD).
-*   [postal_address](https://github.com/googleapis/googleapis/blob/master/google/type/postal_address.proto)
+*   [`postal_address`](https://github.com/googleapis/googleapis/blob/master/google/type/postal_address.proto)
     is a postal address (for example, 1600 Amphitheatre Parkway Mountain View,
     CA 94043 USA).
-*   [color](https://github.com/googleapis/googleapis/blob/master/google/type/color.proto)
+*   [`color`](https://github.com/googleapis/googleapis/blob/master/google/type/color.proto)
     is a color in the RGBA color space.
-*   [month](https://github.com/googleapis/googleapis/blob/master/google/type/month.proto)
+*   [`month`](https://github.com/googleapis/googleapis/blob/master/google/type/month.proto)
     is a month of year (for example, April).
 
 <a id="do-define-widely-used-message-types-in-separate-files"></a>
@@ -140,24 +163,6 @@ used outside your immediate team, consider putting them in their own file with
 no dependencies. Then it's easy for anyone to use those types without
 introducing the transitive dependencies in your other proto files.
 
-<a id="do-reserve-tag-numbers-for-deleted-fields"></a>
-
-## **Do** Reserve Tag Numbers for Deleted Fields {#reserve-tag-numbers}
-
-When you delete a field that's no longer used, reserve its tag number so that no
-one accidentally re-uses it in the future. Just `reserved 2, 3;` is enough. No
-type required (lets you trim dependencies!). You can also reserve names to avoid
-recycling now-deleted field names: `reserved "foo", "bar";`.
-
-<a id="do-reserve-numbers-for-deleted-enum-values"></a>
-
-## **Do** Reserve Numbers for Deleted Enum Values {#reserve-deleted-numbers}
-
-When you delete an enum value that's no longer used, reserve its number so that
-no one accidentally re-uses it in the future. Just `reserved 2, 3;` is enough.
-You can also reserve names to avoid recycling now-deleted value names: `reserved
-"FOO", "BAR";`.
-
 <a id="dont-change-the-default-value-of-a-field"></a>
 
 ## **Don't** Change the Default Value of a Field {#change-default-value}

content/programming-guides/proto2.md

@@ -1141,8 +1141,9 @@ protect participants from reusing extension field numbers.
 
 **Unverified extension field number allocation strategies are not recommended**
 because the [Consequences of Reusing Field Numbers](#consequences) fall on all
-extenders of a message (not just the developer that didn't follow the rules). If
-your use case requires very low coordination, consider using the
+extenders of a message (not just the developer that didn't follow the
+recommendations). If your use case requires very low coordination, consider
+using the
 [`Any` message](/reference/protobuf/google.protobuf#any)
 instead.