# Character Search Parameters

An OCVMax tool uses the following character keys search parameters to distinguish between individual character keys in the string:

Parameter | Description
--- | ---
Accept Threshold | Just as the OCVMax tool uses an accept threshold for the entire string, it uses a separate accept threshold for individual character keys within the string. See the section Matching Scores and Accept Thresholds for more information.
Degrees of Freedom | A character string can undergo a change in various degrees of freedom on a character-to-character basis. This is particularly true of character strings printed on a curved surface, where successive character keys can appear to have changed in their rotation and shear in comparison to one another. See the section Degrees of Freedom for more information on degrees of freedom.
Confusion Values | Confusion values indicate which character keys are similar in appearance to other character keys in the same font. By setting a confusion threshold for these values, you can determine how closely the OCVMax tool will examine character keys that have a similar appearance. See the section Confusion Scores And Confusion Thresholds for more information.