CA1014: Mark assemblies with CLSCompliantAttribute


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Item Value
TypeName MarkAssembliesWithClsCompliant
CheckId CA1014
Category Microsoft.Design
Breaking Change Non-breaking


An assembly does not have the System.CLSCompliantAttribute attribute applied to it.

Rule Description

The Common Language Specification (CLS) defines naming restrictions, data types, and rules to which assemblies must conform if they will be used across programming languages. Good design dictates that all assemblies explicitly indicate CLS compliance with CLSCompliantAttribute. If the attribute is not present on an assembly, the assembly is not compliant.

It is possible for a CLS-compliant assembly to contain types or type members that are not compliant.

How to Fix Violations

To fix a violation of this rule, add the attribute to the assembly. Instead of marking the whole assembly as noncompliant, you should determine which type or type members are not compliant and mark these elements as such. If possible, you should provide a CLS-compliant alternative for noncompliant members so that the widest possible audience can access all the functionality of your assembly.

When to Suppress Warnings

Do not suppress a warning from this rule. If you do not want the assembly to be compliant, apply the attribute and set its value to false.


The following example shows an assembly that has the System.CLSCompliantAttribute attribute applied that declares it CLS-compliant.

using namespace System;

namespace DesignLibrary {}
using System;

namespace DesignLibrary {}
Imports System

Namespace DesignLibrary
End Namespace

See Also

System.CLSCompliantAttribute Language Independence and Language-Independent Components