title: Out of curiosity: How are serial numbers generated? Hints, Algorithms?
body: <p>I wondering about how serial number generators and validator work. My aim would be to generate a serial number with five parts consisting of numbers and letters only.</p>
  
  <p>I enjoy coding as a hobby and would not call myself a professional programmer. However, I am very interested in how those interesting functions work technically to broaden my mind.</p>
  
  <p>Any hints, experiences or written algorithms are appreciated.</p>