To cite package ‘CheckDigit’ in publications use:

Brantley J (2022). CheckDigit: Calculate and Verify Check Digits. R package version 1.0.0, https://gitlab.com/fascinatingfingers/checkdigit.

Corresponding BibTeX entry:

  @Manual{,
    title = {CheckDigit: Calculate and Verify Check Digits},
    author = {Justin Brantley},
    year = {2022},
    note = {R package version 1.0.0},
    url = {https://gitlab.com/fascinatingfingers/checkdigit},
  }