C# Naming Conventions Cheatsheet

Naming Rules by Identifier

Identifier	Convention	Example
Class	PascalCase	`DataService`
Interface	I prefix + PascalCase	`IWorkerQueue`
Struct	PascalCase	`ValueCoordinate`
Delegate	PascalCase	`DelegateType`
Enum	PascalCase — singular (non-flags), plural (flags)	`Color` / `FilePermissions`
Record	PascalCase (params too)	`PhysicalAddress(string Street, ...)`
Namespace	PascalCase — reverse domain notation	`Company.Product.Module`
Public Method	PascalCase	`StartEventProcessing()`
Local Function	PascalCase	`CountQueueItems()`
Public Property	PascalCase	`WorkerQueue`
Public Field	PascalCase	`IsValid`
Public Event	PascalCase	`EventProcessing`
Constant	PascalCase	`MaxRetryCount`
Method Parameter	camelCase	`someNumber`, `isValid`
Local Variable	camelCase	`workerCount`
Private Field	_ prefix + camelCase	`_workerQueue`
Private Static Field	s_ prefix + camelCase	`s_workerQueue`
Thread Static Field	t_ prefix + camelCase	`t_timeSpan`
Attribute Type	PascalCase + Attribute suffix	`ObsoleteAttribute`
Generic Type Param	T prefix + PascalCase	`TSession`, `TOutput`

Primary Constructor Parameters

Type	Convention	Example
class / struct	camelCase — same as regular parameters	`DataService(IWorkerQueue workerQueue)`
record	PascalCase — they become public properties	`Person(string FirstName, string LastName)`

Generic Type Parameter Guidelines

Use descriptive names — prefix with T (e.g., TSession, TInput)
Use single T only when the meaning is obvious: List<T>, Predicate<T>
Consider reflecting constraints in the name: TSession for an ISession constraint

All-in-one Example

namespace Company.Product.Module { public interface IWorkerQueue // I + PascalCase { int Count { get; } } public record PhysicalAddress( // PascalCase params (record) string Street, string City, string ZipCode); public class DataService : IWorkerQueue // PascalCase { private IWorkerQueue _workerQueue; // _ + camelCase private static ILogger s_logger; // s_ + camelCase [ThreadStatic] private static TimeSpan t_elapsed; // t_ + camelCase public bool IsValid; // PascalCase (public field) public const int MaxRetryCount = 3; // PascalCase (constant) public event Action EventProcessing; // PascalCase (event) public void StartProcessing(int retryCount, bool isAsync) // camelCase params { var itemCount = 0; // camelCase (local var) static int CountItems() => 0; // PascalCase (local function) } } public interface ISessionChannel<TSession> // T + descriptive name { TSession Session { get; } } }

General Guidelines

✦ Clarity over brevity. Prefer descriptive names like customerCount over cc. Single-letter names only for simple loop counters.

⚠ No double underscores. Names with __ are reserved for compiler-generated identifiers.

✦ Avoid abbreviations unless widely recognized (e.g., Id, Html, Url are fine).

✦ Enum naming: singular noun for non-flags (Color), plural noun for [Flags] enums (FilePermissions).