meziantou · meziantou · Aug 12, 2026 · Aug 12, 2026
@@ -203,7 +203,7 @@ If you are already using other analyzers, you can check [which rules are duplica
 |[MA0182](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0182.md)|Design|Avoid unused internal types|ℹ️|✔️|✔️|❌|
 |[MA0183](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0183.md)|Usage|The format string should use placeholders|⚠️|✔️|❌|❌|
 |[MA0184](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0184.md)|Style|Do not use interpolated string without parameters|👻|✔️|✔️|❌|
-|[MA0185](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0185.md)|Performance|Simplify string.Create when all parameters are culture invariant|ℹ️|✔️|✔️|❌|
+|[MA0185](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0185.md)|Performance|Simplify string.Create when all parameters are culture invariant|ℹ️|✔️|✔️|✔️|
 |[MA0186](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0186.md)|Design|Equals method should use \[NotNullWhen(true)\] on the parameter|ℹ️|❌|✔️|❌|
 |[MA0187](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0187.md)|Design|Use constructor injection instead of \[Inject\] attribute|ℹ️|❌|✔️|❌|
 |[MA0188](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0188.md)|Design|Use System.TimeProvider instead of a custom time abstraction|ℹ️|✔️|❌|❌|

@@ -11,7 +11,7 @@
 |[MA0008](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0008.md)|Performance|Add StructLayoutAttribute|<span title='Warning'>⚠️</span>|✔️|✔️|❌|
 |[MA0009](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0009.md)|Security|Add regex evaluation timeout|<span title='Warning'>⚠️</span>|✔️|❌|❌|
 |[MA0010](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0010.md)|Design|Mark attributes with AttributeUsageAttribute|<span title='Warning'>⚠️</span>|✔️|✔️|❌|
-|[MA0011](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0011.md)|Usage|IFormatProvider is missing|<span title='Warning'>⚠️</span>|✔️|✔️|<span title='MA0011.consider_nullable_types&#xA;MA0011.exclude_tostring_methods&#xA;MA0011.report_maybe_culture_sensitive'>✔️</span>|
+|[MA0011](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0011.md)|Usage|IFormatProvider is missing|<span title='Warning'>⚠️</span>|✔️|✔️|<span title='MA0011.consider_nullable_types&#xA;MA0011.exclude_tostring_methods&#xA;MA0011.treat_opaque_runtime_types_as_culture_sensitive&#xA;MA0011.treat_unsealed_types_as_culture_sensitive'>✔️</span>|
 |[MA0012](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0012.md)|Design|Do not raise reserved exception type|<span title='Warning'>⚠️</span>|✔️|❌|❌|
 |[MA0013](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0013.md)|Design|Types should not extend System.ApplicationException|<span title='Warning'>⚠️</span>|✔️|❌|❌|
 |[MA0014](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0014.md)|Design|Do not raise System.ApplicationException type|<span title='Warning'>⚠️</span>|✔️|❌|❌|
@@ -74,8 +74,8 @@
 |[MA0072](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0072.md)|Design|Do not throw from a finally block|<span title='Warning'>⚠️</span>|✔️|❌|❌|
 |[MA0073](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0073.md)|Style|Avoid comparison with bool constant|<span title='Info'>ℹ️</span>|✔️|✔️|❌|
 |[MA0074](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0074.md)|Usage|Avoid implicit culture-sensitive methods|<span title='Warning'>⚠️</span>|✔️|✔️|❌|
-|[MA0075](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0075.md)|Design|Do not use implicit culture-sensitive ToString|<span title='Info'>ℹ️</span>|✔️|❌|<span title='MA0075.consider_nullable_types&#xA;MA0075.exclude_tostring_methods&#xA;MA0075.report_maybe_culture_sensitive'>✔️</span>|
-|[MA0076](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0076.md)|Design|Do not use implicit culture-sensitive ToString in interpolated strings|<span title='Info'>ℹ️</span>|✔️|✔️|<span title='MA0076.consider_nullable_types&#xA;MA0076.exclude_tostring_methods&#xA;MA0076.report_maybe_culture_sensitive'>✔️</span>|
+|[MA0075](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0075.md)|Design|Do not use implicit culture-sensitive ToString|<span title='Info'>ℹ️</span>|✔️|❌|<span title='MA0075.consider_nullable_types&#xA;MA0075.exclude_tostring_methods&#xA;MA0075.treat_opaque_runtime_types_as_culture_sensitive&#xA;MA0075.treat_unsealed_types_as_culture_sensitive'>✔️</span>|
+|[MA0076](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0076.md)|Design|Do not use implicit culture-sensitive ToString in interpolated strings|<span title='Info'>ℹ️</span>|✔️|✔️|<span title='MA0076.consider_nullable_types&#xA;MA0076.exclude_tostring_methods&#xA;MA0076.treat_opaque_runtime_types_as_culture_sensitive&#xA;MA0076.treat_unsealed_types_as_culture_sensitive'>✔️</span>|
 |[MA0077](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0077.md)|Design|A class that provides Equals(T) should implement IEquatable\<T\>|<span title='Warning'>⚠️</span>|✔️|✔️|❌|
 |[MA0078](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0078.md)|Performance|Use 'Cast' instead of 'Select' to cast|<span title='Info'>ℹ️</span>|✔️|✔️|❌|
 |[MA0079](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0079.md)|Usage|Forward the CancellationToken using .WithCancellation()|<span title='Info'>ℹ️</span>|✔️|✔️|❌|
@@ -183,7 +183,7 @@
 |[MA0182](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0182.md)|Design|Avoid unused internal types|<span title='Info'>ℹ️</span>|✔️|✔️|❌|
 |[MA0183](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0183.md)|Usage|The format string should use placeholders|<span title='Warning'>⚠️</span>|✔️|❌|❌|
 |[MA0184](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0184.md)|Style|Do not use interpolated string without parameters|<span title='Hidden'>👻</span>|✔️|✔️|❌|
-|[MA0185](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0185.md)|Performance|Simplify string.Create when all parameters are culture invariant|<span title='Info'>ℹ️</span>|✔️|✔️|❌|
+|[MA0185](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0185.md)|Performance|Simplify string.Create when all parameters are culture invariant|<span title='Info'>ℹ️</span>|✔️|✔️|<span title='MA0185.treat_opaque_runtime_types_as_culture_sensitive&#xA;MA0185.treat_unsealed_types_as_culture_sensitive'>✔️</span>|
 |[MA0186](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0186.md)|Design|Equals method should use \[NotNullWhen(true)\] on the parameter|<span title='Info'>ℹ️</span>|❌|✔️|❌|
 |[MA0187](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0187.md)|Design|Use constructor injection instead of \[Inject\] attribute|<span title='Info'>ℹ️</span>|❌|✔️|❌|
 |[MA0188](https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0188.md)|Design|Use System.TimeProvider instead of a custom time abstraction|<span title='Info'>ℹ️</span>|✔️|❌|❌|

@@ -6,7 +6,7 @@ Sources: [UseIFormatProviderAnalyzer.cs](https://github.com/meziantou/Meziantou.
 This rule warns about the usage of overloads of methods like `Parse`, `TryParse` and `ToString` that do not take a parameter of type `IFormatProvider`.
 Methods ending with `OrDefault` are excluded from this rule as the argument is often not relevant for globalization.
 
-The analyzer classifies values as culture-sensitive, culture-insensitive, or maybe culture-sensitive. It reports culture-sensitive values, including types implementing `IFormattable` or `ISpanFormattable` and types with a provider-aware `ToString` overload. Known culture-invariant types, invariant formats and values, sealed types that do not support culture-aware formatting, and types marked with `CultureInsensitiveTypeAttribute` are culture-insensitive. Values typed as `object`, an interface, a type parameter, or a non-sealed class are maybe culture-sensitive because their runtime type can format differently. They are not reported by default; set `MA0011.report_maybe_culture_sensitive` to `true` to report them.
+The analyzer classifies values as culture-sensitive, culture-insensitive, opaque runtime types, or non-sealed types. It reports culture-sensitive values, including types implementing `IFormattable` or `ISpanFormattable` and types with a provider-aware `ToString` overload. Known culture-invariant types, invariant formats and values, sealed types that do not support culture-aware formatting, and types marked with `CultureInsensitiveTypeAttribute` are culture-insensitive. Values typed as `object`, an interface, or an unconstrained type parameter are opaque runtime types. Non-sealed classes are tracked separately. These two categories are not reported by default; set `MA0011.treat_opaque_runtime_types_as_culture_sensitive` or `MA0011.treat_unsealed_types_as_culture_sensitive` to `true` to report them.
 
 For more information, see [Creating Globally Aware Applications](https://learn.microsoft.com/en-us/previous-versions/windows/silverlight/dotnet-windows-silverlight/cc853414(v=vs.95)?WT.mc_id=DT-MVP-5003978).
 
@@ -41,8 +41,11 @@ MA0011.exclude_tostring_methods=true
 # Report Nullable<T>.ToString when T is culture-sensitive
 MA0011.consider_nullable_types=true
 
-# Report values that may be culture-sensitive based on their runtime type
-MA0011.report_maybe_culture_sensitive=true
+# Report object, interface, and unconstrained type parameter values
+MA0011.treat_opaque_runtime_types_as_culture_sensitive=false
+
+# Report non-sealed class values
+MA0011.treat_unsealed_types_as_culture_sensitive=false
 ````
 
 You can also annotate a type with `[Meziantou.Analyzer.Annotations.CultureInsensitiveTypeAttribute]` to disable the rule for this type. See [CultureInsensitiveTypeAttribute](../CultureInsensitiveTypeAttribute.md) for details and [Meziantou.Analyzer.Annotations README](https://github.com/meziantou/Meziantou.Analyzer/blob/main/src/Meziantou.Analyzer.Annotations/README.md) for installation options.
@@ -13,7 +13,7 @@ _ = "abc" + -1.ToString(CultureInfo.CurrentCulture);   // compliant
 _ = "abc" + -1.ToString(CultureInfo.InvariantCulture); // compliant
 ````
 
-A type is culture-sensitive when it implements `System.IFormattable` or `System.ISpanFormattable`, or exposes a provider-aware `ToString` overload. A type is culture-insensitive when it is known to be invariant, is marked with `CultureInsensitiveTypeAttribute`, or is sealed and does not support culture-aware formatting. Values typed as `object`, an interface, a type parameter, or a non-sealed class are maybe culture-sensitive because their runtime type can format differently. They are not reported by default; set `MA0075.report_maybe_culture_sensitive` to `true` to report them.<br/>
+A type is culture-sensitive when it implements `System.IFormattable` or `System.ISpanFormattable`, or exposes a provider-aware `ToString` overload. A type is culture-insensitive when it is known to be invariant, is marked with `CultureInsensitiveTypeAttribute`, or is sealed and does not support culture-aware formatting. Values typed as `object`, an interface, or an unconstrained type parameter are opaque runtime types. Non-sealed classes are tracked separately. These two categories are not reported by default; set `MA0075.treat_opaque_runtime_types_as_culture_sensitive` or `MA0075.treat_unsealed_types_as_culture_sensitive` to `true` to report them.<br/>
 Known culture-invariant types include:
 * Any enum
 * System.Byte
@@ -44,8 +44,11 @@ MA0075.exclude_tostring_methods=true
 # Report Nullable<T>.ToString when T is culture-sensitive
 MA0075.consider_nullable_types=true
 
-# Report values that may be culture-sensitive based on their runtime type
-MA0075.report_maybe_culture_sensitive=true
+# Report object, interface, and unconstrained type parameter values
+MA0075.treat_opaque_runtime_types_as_culture_sensitive=false
+
+# Report non-sealed class values
+MA0075.treat_unsealed_types_as_culture_sensitive=false
 ````
 
 You can also annotate a type with `[Meziantou.Analyzer.Annotations.CultureInsensitiveTypeAttribute]` to disable the rule for this type. See [CultureInsensitiveTypeAttribute](../CultureInsensitiveTypeAttribute.md) for details and [Meziantou.Analyzer.Annotations README](https://github.com/meziantou/Meziantou.Analyzer/blob/main/src/Meziantou.Analyzer.Annotations/README.md) for installation options.
@@ -11,7 +11,7 @@ _ = string.Create(CultureInfo.InvariantCulture, $"abc{-1}"); // compliant
 FormattableString str = $"abc{-1}"; // compliant
 ````
 
-The analyzer classifies values as culture-sensitive, culture-insensitive, or maybe culture-sensitive. It reports culture-sensitive values, including types implementing `IFormattable` or `ISpanFormattable` and types with a provider-aware `ToString` overload. Known culture-invariant types, invariant formats and values, sealed types that do not support culture-aware formatting, and types marked with `CultureInsensitiveTypeAttribute` are culture-insensitive. Values typed as `object`, an interface, a type parameter, or a non-sealed class are maybe culture-sensitive because their runtime type can format differently. They are not reported by default; set `MA0076.report_maybe_culture_sensitive` to `true` to report them.
+The analyzer classifies values as culture-sensitive, culture-insensitive, opaque runtime types, or non-sealed types. It reports culture-sensitive values, including types implementing `IFormattable` or `ISpanFormattable` and types with a provider-aware `ToString` overload. Known culture-invariant types, invariant formats and values, sealed types that do not support culture-aware formatting, and types marked with `CultureInsensitiveTypeAttribute` are culture-insensitive. Values typed as `object`, an interface, or an unconstrained type parameter are opaque runtime types. Non-sealed classes are tracked separately. These two categories are not reported by default; set `MA0076.treat_opaque_runtime_types_as_culture_sensitive` or `MA0076.treat_unsealed_types_as_culture_sensitive` to `true` to report them.
 
 ## Configuration
 
@@ -22,8 +22,11 @@ MA0076.exclude_tostring_methods=true
 # Report Nullable<T>.ToString when T is culture-sensitive
 MA0076.consider_nullable_types=true
 
-# Report values that may be culture-sensitive based on their runtime type
-MA0076.report_maybe_culture_sensitive=true
+# Report object, interface, and unconstrained type parameter values
+MA0076.treat_opaque_runtime_types_as_culture_sensitive=false
+
+# Report non-sealed class values
+MA0076.treat_unsealed_types_as_culture_sensitive=false
 ````
 
 You can also annotate a type with `[Meziantou.Analyzer.Annotations.CultureInsensitiveTypeAttribute]` to disable the rule for this type. See [CultureInsensitiveTypeAttribute](../CultureInsensitiveTypeAttribute.md) for details and [Meziantou.Analyzer.Annotations README](https://github.com/meziantou/Meziantou.Analyzer/blob/main/src/Meziantou.Analyzer.Annotations/README.md) for installation options.
@@ -29,10 +29,23 @@ The analyzer detects when all interpolated values are culture-invariant, such as
 - Enum values
 - Boolean values
 - and other culture-insensitive types
+- Opaque runtime types such as `object`, interfaces, and unconstrained type parameters, unless `MA0185.treat_opaque_runtime_types_as_culture_sensitive` is enabled
+- Non-sealed classes, unless `MA0185.treat_unsealed_types_as_culture_sensitive` is enabled
 
 You can annotate custom types with `[Meziantou.Analyzer.Annotations.CultureInsensitiveTypeAttribute]` to mark them as culture-insensitive and make additional `string.Create(CultureInfo.InvariantCulture, ...)` usages eligible for simplification. See [CultureInsensitiveTypeAttribute](../CultureInsensitiveTypeAttribute.md) for details and [Meziantou.Analyzer.Annotations README](https://github.com/meziantou/Meziantou.Analyzer/blob/main/src/Meziantou.Analyzer.Annotations/README.md) for installation options.
 
 The analyzer will NOT suggest simplification when:
 - Any parameter is culture-sensitive (e.g., `double`, `DateTime` with culture-sensitive format)
-- A parameter is maybe culture-sensitive, such as one typed as `object`, an interface, a type parameter, or a non-sealed class, as its runtime type may format differently. This rule requires proof that all parameters are culture-insensitive.
+- A parameter is an opaque runtime type and `MA0185.treat_opaque_runtime_types_as_culture_sensitive` is enabled
+- A parameter is a non-sealed class and `MA0185.treat_unsealed_types_as_culture_sensitive` is enabled
 - The culture is not `CultureInfo.InvariantCulture`
+
+## Configuration
+
+````
+# Treat object, interface, and unconstrained type parameter values as culture-sensitive
+MA0185.treat_opaque_runtime_types_as_culture_sensitive=false
+
+# Treat non-sealed class values as culture-sensitive
+MA0185.treat_unsealed_types_as_culture_sensitive=false
+````