Update identity-resolution-settings.md Changing Identity Resolution Rules

Author: lizkane222

src/unify/identity-resolution/identity-resolution-settings.md

@@ -19,6 +19,11 @@ Before you connect a source to Unify, Segment recommends that you first review t
 > note ""
 > **NOTE:** Workspace owners and users with the Identity Admin role can edit the Identity Resolution table.
 
+> note ""
+> **NOTE:** When changing an Engage Space's Identity Resolution Rules, please keep the following in mind as changes will have impacts on existing profiles :
+> Making a space's Identity Resolution Rules less restrictive by changing the [Limit](https://segment.com/docs/unify/identity-resolution/identity-resolution-settings/#limit) shouldn't cause any issues to existing or future profiles. Though making a space's Identity Resolution Rules more restrictive after profiles exist then that could have serious impacts on existing profiles that already exist outside the bounds of the more restrictive rules, such as with decreasing an identifier's Limit or changing the [Priority](https://segment.com/docs/unify/identity-resolution/identity-resolution-settings/#priority) of identifiers.
+> The recommended approach is to get started with a Dev space [here](https://segment.com/docs/unify/identity-resolution/space-setup/), test the rules with the expected data, and then create an identical Production space with those rules. When making any changes to a space's Identity Resolution Rules, make sure your team documents those changes to ensure changes don't cause breaking changes to profiles, and do not to update the Identity Resolution Rules to be more restrictive after profiles already exist outside the bounds of those new limitations. 
+
 ## ExternalIDs
 
 Segment creates and merges user profiles based on externalIDs used as identifiers. You can view these externalIDs in the Identities tab of a User Profile in the Profile explorer.