Code 93 was designed to supplement and improve upon Code 39.
Code 93 is similar in that, like Code 39, can represent the full ASCII character set by using combinations of 2 characters. It differs in that Code 93 is a continuous symbology and produces denser code. It also encodes 47 characters (compared to Code 39's 43 characters).
The following property is specific to the Code 93 type and available in the Properties panel under the Symbology property:
Calculate a Checksum
Specifies whether to calculate a checksum for the bar code.
A checksum of a Code 93 bar code can contain characters that are not supported by this bar code symbology. For this reason, the checksum is not included in the Code 93 bar code's displayed text.