Objective: Warn tech in an obvious way to handle customer or contact in non-standard manner such as:
"Don't call this person She or Her" (contact note)
"Don't service until they pay" (company note)
"All requests for new licenses must be approved by Mr. X" (company note)

Method ideas:
1. Ability to enter info at customer or contact level, very much like Notes but distinct from that field. If static (vs user defined) field, named "Critical notes" or something.
2. On Add Ticket screen, as soon as pick Customer, display associated Critical Notes via popup or highlighted area. Upon pick of Contact,display Critical Notes associated with Contact AND Customer via popup or highlighted area,
3. For emailed tickets (in other words, normal existing Ticket screen show Critical Notes for Customer AND Contact in a highlighted manner