Below are few more things one should know about Business Rules in CRM 2015:
• The rules need to be activated before they take effect (similar to workflows).
• You can specify whether the rule applies to all forms or specific forms.
• The rules fire in the new mobile client for iPad and Windows 8.
• The rules are client-side rules, they do not fire during API calls, data import, etc. Microsoft’s vision is to add that support in a future release.
• If your rule hides a field then CRM moves fields up to close the gap.
• You need to consider the inverse of your rule i.e. in my example I tell CRM what to do when the Est. Revenue field contains data. I don’t tell it what to do when the Est. Revenue does not contain data. I need to write a second Business Rule for that.
• String comparisons are case sensitive.