Since we do not store what codes were generated by the generator, there is a chance that another user will set an identical generator configuration and, as a result, some of the codes will be identical to yours. If you want to ensure that the codes you generate will never be repeated by anyone else, set the maximum range of characters from which they can be generated and the maximum length possible. It's also a good idea to add a prefix that will be associated with you in some way, so there is a small chance that someone will type the same one. For example, if you use all lowercase and uppercase letters and special characters, and your code is 20 characters long, there are as many as 1,516,449,130,501,757,800,000,000,000,000,000,000,000 possible code variants to generate. For example, if you and someone else generate 1,000 codes, the chance that they will be repeated is close to zero.