What is double titration and give an exampleof double titration

Double titration means two titrations are done in a process. In this process:The first titration is done to standardize the titrant (usually taken in burette).The second titration is used to find the molarity of the titrand (unknown solution and taken in conical flask).For example, we have to calculate molarity of HCl acid by titrating it with NaOH base. But for that NaOH must also be standardized.So for the whole process, we do double titration. First we standardize NaOH by titrating it with a standard oxalic acid solution. And then, we find out the molarity of HCl by titrating it with standardized NaOH solution.