A using-alias directive is positioned before a regular using directive.
A violation of this rule occurs when a using-alias directive is placed before a normal using directive. Using-alias directives have special behavior which can alter the meaning of the rest of the code within the file or namespace. Placing the using-alias directives together below all other using-directives can make the code cleaner and easier to read, and can help make it easier to identify the types used throughout the code.
How to fix violations
To fix an instance of this violation, place all using-alias directives beneath all normal using directives.
How to suppress violations
[SuppressMessage("StyleCop.CSharp.OrderingRules", "SA1209:UsingAliasDirectivesMustBePlacedAfterOtherUsingDirectives", Justification = "Reviewed.")]
#pragma warning disable SA1209 // UsingAliasDirectivesMustBePlacedAfterOtherUsingDirectives #pragma warning restore SA1209 // UsingAliasDirectivesMustBePlacedAfterOtherUsingDirectives