Improved Scorch
Client records describe this reading. They do not confirm availability in gameplay.
Current client record
Your Scorch spell has a 100% chance to cause your target to be vulnerable to Fire damage. This vulnerability increases all Fire damage you deal to your target by 3% and lasts 30 sec, stacking up to 5 times.
Sourced change history
No changes in the tracked log could be matched to this record. This does not mean the ability or item has never changed.