1 Introduction  
2 Evolution of Hallucination in NLP  
3 Social Perspectives on Hallucinations  
4 Critical Analysis of Hallucination in NLP  
4.1 Conceptualization of Hallucination  
4.2 Audit of Frameworks  
4.3 Audit of Metrics  
5 Practitioner Survey of Hallucination  
5.1 Survey Recruitment and Data Collection  
5.2 Survey Structure  
5.3 Survey Findings  
5.4 An External Viewpoint  
5.5 Additional Impacts and Concerns  
6 Research Challenges and Recommendations  
6.1 Challenges  
6.2 Recommendations  
6.2.1 Author-Centric Recommendation  
6.2.2 Community-Centric Recommendation  
7 Conclusion