Syntactic indexing public doc

docs/code-search/code-navigation/syntactic_code_navigation.mdx

@@ -0,0 +1,59 @@
+# Syntactic Code Navigation
+
+<TierCallout>
+  Supported on [Enterprise](/pricing/enterprise) plans.
+  <user>
+   This feature is currently in Beta and enabled by default for Cloud customers
+  </user>
+</TierCallout>
+
+Syntactic code navigation is a zero configuration feature that improves code navigation for certain languages in the absence of
+[Precise code navigation](./precise_code_navigation) set up. It works by periodically indexing repositories for which it is [enabled](#enabling-syntactic-code-navigation), using high level syntax analysis heuristics.
+
+This mechanism is more robust than search-based navigation, but less powerful than Precise code navigation.
+When syntactic indexing data is available for a given file and repository, it will be selected over search-based navigation automatically,
+but only if Precise data is not available. To summarize, the order of priorities is as follows:
+
+- Precise data
+- Syntactic, if no precise data available
+- Search-based, if no syntactic available
+
+## Enabling Syntactic code navigation
+
+First, enable the experimental feature flag in Site config:
+
+```json
+  "experimentalFeatures.codeintelSyntacticIndexing.enabled": true
+```
+
+Next, you need to ensure that syntactic indexing is enabled in a code graph configuration policy. Note that for cloud customers this feature is enabled by default for all repositories, as part of
+automatically managed policy called `[Sourcegraph Managed] Head of default branch policy`.
+
+For all other deployments, you will need to create a HEAD policy with "Syntactic indexing" enabled:
+
+![Screenshot of sourcegraph interface demonstrating Syntactic indexing toggle enabled for a code graph policy](https://storage.googleapis.com/sourcegraph-assets/Docs/syntactic-indexing-policy.png)
+
+Syntactic indexing can only be enabled if the policy type is set to HEAD – only indexing the tip of default branch on each repository. You may choose to apply this policy only to selected repositories, although the recommendation is to enable it instance-wide.
+
+## Supported languages
+
+Syntactic code navigation requires language-specific implementations, and we currently support the following languages: 
+
+ - [Java](https://www.java.com/en/) 
+ - [Go](https://go.dev/)
+ - [Scala](https://scala-lang.org)
+ - [C#](https://learn.microsoft.com/en-us/dotnet/csharp/)
+ - [C++](https://isocpp.org/)
+
+We are constantly looking to expand the list of supported languages, with Python, Typescript/Javascript, and C planned. 
+If you are interested in syntactic indexing for these or any other languages, please contact your Sourcegraph account representative.
+
+## Comparison with Precise and Search-based
+
+Syntactic code navigation falls between Precise and Search-based code navigation both in terms of quality of navigation,
+and in terms of effort to maintain for different languages:
+
+![Comparison chart showing where different navigation modes are located in terms of effort to maintain and quality of results](https://storage.googleapis.com/sourcegraph-assets/Docs/code-navigation-levels-comparison.png)
+
+As the indexing does not involve build tools or actual compilers, it can be performed in isolated environment, with no network access
+and no configuration, unlike Precise.

src/data/navigation.ts

@@ -105,6 +105,7 @@ export const navigation: NavigationItem[] = [
 							{ title: "Features", href: "/code-search/code-navigation/features", },
 							{ title: "Search-based code navigation", href: "/code-search/code-navigation/search_based_code_navigation", },
 							{ title: "Precise code navigation", href: "/code-search/code-navigation/precise_code_navigation", },
+							{ title: "Syntactic code navigation", href: "/code-search/code-navigation/syntactic_code_navigation", },
 							{ title: "Auto-indexing", href: "/code-search/code-navigation/auto_indexing", },
 							{ title: "Environment Variables", href: "/code-search/code-navigation/envvars", },
 							{ title: "Troubleshooting", href: "/code-search/code-navigation/troubleshooting", },