Fix typo (#23980)

Author: Youssef1313

docs/csharp/language-reference/compiler-options/security.md

@@ -29,7 +29,7 @@ This option causes the compiler to apply a public key but doesn't actually sign
 <PublicSign>true</PublicSign>
 ```
 
-The **PublicSign** option requires the use of the [**KeyFile**](#keyfile) or [**KeyContainer**](#keycontainer) option. The **keyFile** and **KeyContainer** options specify the public key. The **PublicSign** and **PublicSign** options are mutually exclusive. Sometimes called "fake sign" or "OSS sign", public signing includes the public key in an output assembly and sets the "signed" flag. Public signing doesn't actually sign the assembly with a private key. Developers use public sign for open-source projects.  People build assemblies that are compatible with the released "fully signed" assemblies when they don' have access to the private key used to sign the assemblies. Since few consumers actually need to check if the assembly is fully signed, these publicly built assemblies are useable in almost every scenario where the fully signed one would be used.
+The **PublicSign** option requires the use of the [**KeyFile**](#keyfile) or [**KeyContainer**](#keycontainer) option. The **keyFile** and **KeyContainer** options specify the public key. The **PublicSign** and **DelaySign** options are mutually exclusive. Sometimes called "fake sign" or "OSS sign", public signing includes the public key in an output assembly and sets the "signed" flag. Public signing doesn't actually sign the assembly with a private key. Developers use public sign for open-source projects.  People build assemblies that are compatible with the released "fully signed" assemblies when they don' have access to the private key used to sign the assemblies. Since few consumers actually need to check if the assembly is fully signed, these publicly built assemblies are useable in almost every scenario where the fully signed one would be used.
 
 ## DelaySign