# CA1707: Identifiers should not contain underscores

Value
Rule ID CA1707
Category Naming
Fix is breaking or non-breaking Breaking - when raised on assemblies

Non-breaking - when raised on type parameters

## Cause

The name of an identifier contains the underscore (_) character.

## Rule description

By convention, identifier names do not contain the underscore (_) character. The rule checks namespaces, types, members, and parameters.

Naming conventions provide a common look for libraries that target the common language runtime. This reduces the learning curve that is required for new software libraries, and increases customer confidence that the library was developed by someone who has expertise in developing managed code.

## How to fix violations

Remove all underscore characters from the name.

## When to suppress warnings

Do not suppress warnings for production code. However, it's safe to suppress this warning for test code. You can suppress warnings from this rule by setting its severity to none.

For well-known methods in Microsoft code that currently use an underscore and cannot be modified, the rule should be suppressed.

## Configure code to analyze

Use the following option to configure which parts of your codebase to run this rule on.

You can configure this option for just this rule, for all rules, or for all rules in this category (Naming). For more information, see Code quality rule configuration options.

### Include specific API surfaces

You can configure which parts of your codebase to run this rule on, based on their accessibility. For example, to specify that the rule should run only against the non-public API surface, add the following key-value pair to an .editorconfig file in your project:

dotnet_code_quality.CAXXXX.api_surface = private, internal