What is jarḥ ghayr mufassar?

Narrator Anonymity: Wuḥdān, Mubham, Majhūl al-ʿAyn and Mastūr

• All the person’s chains being mutawātir
• Unqualified endorsement without scrutiny
• Omitting the teacher’s name from the chain
• A critical allegation is stated without elaborating its grounds