Update DebugType documentation to clarify default behavior and show how to disable PDB generation for Release builds

Co-authored-by: BillWagner <[email protected]>

Author: Copilot

docs/csharp/language-reference/compiler-options/code-generation.md

@@ -24,14 +24,35 @@ The following options control code generation by the compiler. The new MSBuild s
 
 ## DebugType
 
-The **DebugType** option causes the compiler to generate debugging information and place it in the output file or files. Debugging information is added by default.
+The **DebugType** option causes the compiler to generate debugging information and place it in the output file or files. The default value is `portable` for both Debug and Release build configurations, which means PDB files are generated by default for all configurations.
 
 ```xml
 <DebugType>pdbonly</DebugType>
 ```
 
 For all compiler versions starting with C# 6.0, there is no difference between *pdbonly* and *full*. Choose *pdbonly*. To change the location of the *.pdb* file, see [**PdbFile**](./advanced.md#pdbfile).
 
+### Disabling PDB generation for Release builds
+
+To suppress PDB file generation for Release builds while keeping them for Debug builds, add the following to your project file:
+
+```xml
+<PropertyGroup Condition="'$(Configuration)' == 'Release'">
+  <DebugType>none</DebugType>
+</PropertyGroup>
+```
+
+Alternatively, you can set `DebugSymbols` to `false` for Release builds:
+
+```xml
+<PropertyGroup Condition="'$(Configuration)' == 'Release'">
+  <DebugSymbols>false</DebugSymbols>
+</PropertyGroup>
+```
+
+> [!NOTE]
+> In .NET 8 and later versions, setting `DebugSymbols` to `false` should suppress PDB generation according to the [breaking change documentation](../../../core/compatibility/sdk/8.0/debugsymbols.md). However, for the most reliable way to disable PDB generation, explicitly set `DebugType` to `none`.
+
 The following values are valid:
 
 | Value      | Meaning                                                                                                 |
@@ -40,6 +61,7 @@ The following values are valid:
 | `pdbonly`  | Same as `full`. See the note below for more information. |
 | `portable` | Emit debugging information to .pdb file using cross-platform [Portable PDB](https://github.com/dotnet/designs/blob/main/accepted/2020/diagnostics/portable-pdb.md) format. |
 | `embedded` | Emit debugging information into the _.dll/.exe_ itself (_.pdb_ file is not produced) using [Portable PDB](https://github.com/dotnet/designs/blob/main/accepted/2020/diagnostics/portable-pdb.md) format. |
+| `none`     | Don't produce a PDB file.                                                                              |
 
 > [!IMPORTANT]
 > The following information applies only to compilers older than C# 6.0.