To ensure the same rule is not created by you or another user (could be your bookkeeper) you will get notified if the rule you're creating is the same as (duplicate) or similar to an existing rule. 

A duplicate rule means that there is an existing rule that has the exact same IF (Type, Occurs in & Description) and Then (Name and/or Category) selected. 

• Note: You will not be allowed to save a duplicate rule. You will be asked to edit your rule to make the necessary changes so it doesn't affect the same transactions.

A similar rule means that there is one or more existing rules that are similar to the rule you’re creating. Similar rules is identified on the following conditions:

• The description is the same or similar (some words are the same)

• The vendor/customer selected is the same

You have the option to edit your rule or proceed with the rule you’re creating.