I. Introduction

II. Background and Definition  
B. Taxonomy of UDTL-based IFD  
C. Motivation of UDTL-based IFD  
D. The structure of backbone  

III. Label-Consistent UDTL

IV. Label-Inconsistent UDTL

V. Multi-Domain UDTL

VI. Datasets  

VII. Comparative Studies  

VIII. Further Discussions  

IX. Conclusion