Computer program for the calculation and validation
of Verhoeff check digits

Abundance estimates from tag-release and tag-recapture data require that the number and type of errors in data for analysis are minimised. Accurate recording of the sequence numbers on tags at time of release and recapture form an important part of data accuracy. Check digits, as a part of the tag sequence number, can assist in the identification of errors in recorded data.
A computer program to calculate, check, and validate a check digit scheme based on Verhoeff's Dihedral Group D5 check algorithm (Mohr 2005, Verhoeff 1969) is described.