This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature.
The IsVariableLength property specifies data length representation handling for a data type.
If TRUE, the data type represents strings that vary in length, such as those defined as varchar(4).
If FALSE, the data type does not represent strings that vary in length, such as those defined as char(4).
Variability in string representation is easily visible in client software. For example, the string AK retrieved from a column defined as varchar(4) is returned to a client as two characters. If retrieved from a column defined as char(4), the string is padded using a space character so that four characters are returned.