# Swap Characters

The classification process can optionally accept a swap character set (OCRMaxSwapCharSet) to specify characters in the trained font which can be ignored when calculating a matching score.

Use swap characters to prevent the OCRMax tool from generating confused results by an otherwise understandable string due to the similarity between two or more characters which are known to have a similar appearance, such as a "0" (zero) and a capital letter "O".

If a swap character set is specified, then the confidence score is defined as the difference between the score of the highest scoring classification and the score of the next-highest classification which is not swappable with the highest scoring classification.