The code below is taken from the sp_executesql page in sql books online.

On the last but one line there is an 'N' before the literal.

Anyone know what it means?

/* Show not having access to variables from the calling batch. */
DECLARE @CharVariable CHAR(3)
SET @CharVariable = 'abc'
/* sp_executesql fails because @CharVariable has gone out of scope. */
sp_executesql N'PRINT @CharVariable'
GO

The 'N' is a qualifier signifying a UNICODE string. Thus, the expression:
indicates that the string enclosed in quotes should be encoded as a UNICODE string, rather than the default encoding on the server it is running on. This guarantees that the string and the '@' especially, will be correctly interpreted even if the code is run on a server configured in Sanskrit, for example.

Not necessary if you're running the Latin character sets, but documentation writers can't guarantee that...

Jeff Mason
Custom Apps, Inc.
www.custom-apps.com

Thanks that makes it clear.