CA1014: Mark assemblies with CLSCompliantAttribute

Property Value
Rule ID CA1014
Title Mark assemblies with CLSCompliantAttribute
Category Design
Fix is breaking or non-breaking Non-breaking
Enabled by default in .NET 8 No


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.

Suppress a warning

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable CA1014
// The code that's violating the rule is on this line.
#pragma warning restore CA1014

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

dotnet_diagnostic.CA1014.severity = none

For more information, see How to suppress code analysis warnings.


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

namespace DesignLibrary {}
Namespace DesignLibrary
End Namespace

See also