feat(tracing): Add searchable span properties

docs/concepts/search/searchable-properties/events.mdx

@@ -480,7 +480,8 @@ Returns results with an approximate percentile of the field to the level. The le
 
 ### `platform`
 
-Name of the platform. This is only a metrics property for [valid platforms](https://github.com/getsentry/relay/blob/9d0d2dc54233d46043a369e1dacf7db900953c14/relay-general/src/protocol/constants.rs#L1-L21), defaulting to `other`.
+Name of the platform. This defaults to `other` and is only a property for platforms from this list:
+`as3`, `c`, `cfml`, `cocoa`, `csharp`, `elixir`, `go`, `groovy`, `haskell`, `java`, `javascript`, `native`, `node`, `objc`, `other`, `perl`, `php`, `python`, `ruby`
 
 - **Type:** string
 

docs/concepts/search/searchable-properties/index.mdx

@@ -12,6 +12,7 @@ Sentry's searchable properties fall into one of five categories:
 
 - [Issue properties](/product/sentry-basics/search/searchable-properties/issues/)
 - [Event properties](/product/sentry-basics/search/searchable-properties/events/)
+- [Span properties](/concepts/search/searchable-properties/spans/)
 - [Session Replay properties](/product/sentry-basics/search/searchable-properties/session-replay/)
 - [User Feedback properties](/product/sentry-basics/search/searchable-properties/user-feedback/)
 - [Release properties](/product/sentry-basics/search/searchable-properties/releases/)

docs/concepts/search/searchable-properties/spans.mdx

@@ -0,0 +1,191 @@
+---
+title: Span Properties
+description: "Learn more about searchable span properties."
+sidebar_order: 21
+---
+
+Spans are the underlying data element captured in Sentry SDKs that together make up a trace.
+
+You can search by span properties in the following [Sentry](https://sentry.io) pages:
+
+- Traces - when searching for a trace containing spans with matching properties
+
+When you search for span properties within the **Traces** page, the search will return any trace that contains _one or more spans_ that match your span properties filter.
+
+## Searchable Properties
+
+Below is a list of keys and tokens that can be used in the span search:
+
+<DefinitionList>
+
+### `action`
+
+The type of span action.
+
+- **Type:** string
+
+### `browser.name`
+
+The name of the browser that generated the span.
+
+- **Type:** string
+
+### `cache.hit`
+
+Whether a cache read has hit or missed the queried cache key. Values are `'true'` or `'false'`.
+
+- **Type:** string
+
+### `description`
+
+Parameterized and scrubbed description of the span.
+
+- **Type:** string
+
+### `device.class`
+
+Device class is a synthesized field that's calculated by using device info found in context such as model (for iOS devices), and device specs like processor_frequency (for Android devices).
+
+- **Type:** string
+
+### `environment`
+
+Refers to your code deployment naming convention. For example, `development`, `testing`, `staging` and so on. [Learn more](/product/sentry-basics/environments/). In some pages of [Sentry](https://sentry.io/), you filter on environment using a dropdown.
+
+- **Type:** string
+
+### `file_extension`
+
+The file extension of a resource span.
+
+- **Type:** string
+
+### `http.decoded_response_content_length`
+
+The [decoded body size](https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming/decodedBodySize) of the resource.
+
+- **Type:** string
+
+### `http.response_content_length`
+
+The [encoded body size](https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming/encodedBodySize) of the resource.
+
+- **Type:** string
+
+### `http.response_transfer_size`
+
+The [total transfer size](https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming/transferSize) of the resource.
+
+- **Type:** string
+
+### `messaging.destination.name`
+
+The queue name or topic that the message is written or published to. The consumer also reads from this queue.
+
+- **Type:** string
+
+### `messaging.message.id`
+
+The unique ID of a message from the queue or messaging system.
+
+- **Type:** string
+
+### `op`
+
+Span operation.
+
+- **Type:** string
+
+### `os.name`
+
+Name of the operating system.
+
+- **Type:** string
+
+### `platform`
+
+Name of the platform. This defaults to `other` and is only a property for platforms from this list:
+`as3`, `c`, `cfml`, `cocoa`, `csharp`, `elixir`, `go`, `groovy`, `haskell`, `java`, `javascript`, `native`, `node`, `objc`, `other`, `perl`, `php`, `python`, `ruby`
+
+- **Type:** string
+
+### `release`
+
+A release is a version of your code deployed to an environment. You can create a token that matches a release exactly, or pick the most recent release by using `release:latest`.
+
+- **Type:** string
+
+### `resource.render_blocking_status`
+
+The [render blocking status](https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming/renderBlockingStatus) of the resource.
+
+- **Type:** string
+
+### `sdk.name`
+
+Name of the Sentry SDK that sent the event.
+
+- **Type:** string
+
+### `sdk.version`
+
+Version of the Sentry SDK that sent the event.
+
+- **Type:** string
+
+### `status_code`
+
+The HTTP response status code.
+
+- **Type:** string
+
+### `system`
+
+Database system (e.g., `postresql` or `mysql`).
+
+- **Type:** string
+
+### `trace.status`
+
+The span trace's success or failure status.
+
+- **Type:** string
+
+### `transaction`
+
+Name of the containing transaction.
+
+- **Type:** string
+
+
+### `transaction.method`
+
+HTTP method of the containing transaction.
+
+- **Type:** string
+
+### `transaction.op`
+
+Operation of the containing transaction.
+
+- **Type:** string
+
+### `user.email`
+
+An alternative or addition to the username. Sentry is aware of email addresses and can therefore display things such as Gravatars and unlock messaging capabilities.
+
+- **Type:** string
+
+### `user.id`
+
+Application-specific internal identifier for the user.
+
+- **Type:** string
+
+### `user.username`
+
+Username, which is typically a better label than user.id.
+
+- **Type:** string
+
+</DefinitionList>