2.2 Identifiers and Keywords

Identifiers are names programmers choose for their types, methods, variables, etc. An identifier must be a whole word, essentially made up of Unicode characters starting with a letter or underscore, and may not clash with a keyword. As a special case, the @ prefix may be used to avoid a clash with a keyword, but is not considered part of the identifier. For instance, the following two identifiers are equivalent:

Kon @Kon

C# identifiers are case-sensitive, though for compatibility with other languages, you should not differentiate public or protected identifiers by case alone.

Here is a list of C# keywords:

abstract	as	base	bool	break
byte	case	catch	char	checked
class	const	continue	decimal	default
delegate	do	double	else	enum
event	explicit	extern	false	finally
fixed	float	for	foreach	goto
if	implicit	in	int	interface
internal	is	lock	long	namespace
new	null	object	operator	out
override	params	private	protected	public
readonly	ref	return	sbyte	sealed
short	sizeof	stackalloc	static	string
struct	switch	this	throw	true
try	typeof	uint	ulong	unchecked
unsafe	ushort	using	virtual	void
while