How do you properly write parse rules to remove leading zeros only?

Summary: Per this article - I created a cascading parse rule on transaction type 475 to remove leading zeros.

1. If it’s known how many leading zeros needs to be eliminated, you can create the following rule and assign to one or more banks:
   000000(X~)
   Ex: To parse 00000025221 into 25221 you can define parse rule with rule 000000(X~), and to remove leading numbers before "_" use the rule, _(X~)
   
   
2. When the number of leading zeros is unknown, you can create multiple sequences for the same Source Field.
   Each sequence will remove a different number of leading zeros. In this case, the sequence is very important to achieve the correct result.