This counter value can be used if you need a consecutive number series for used Budget Categories and Accounts.
Budget Categories and Accounts can have numbers or letters. This could be used for internal Account Structure purposes. However if you need to add a counter to your quotes, those numbers would not be consecutive, but fixed.
This is why a "Counter" element has been added to the Budgeting window.
You can show this Counter by clicking on the eye menu > Edit View > Counter.
Here an example how the counter vs the Category and Account numbers looks like:
In the quote print out you can add the counter from the Category or Accounts loop: