1 Introduction
2 Preliminaries
2.1 Federated Learning (FL)
2.2 Machine Learning with Unlabeled Data
3 Federated Semi-supervised Learning
3.1 The Label-at-client Setting
3.2 The Label-at-server Setting
4 Federated Self-supervised Learning
5 Federated Transfer Learning
5.1 Homogeneous FTL
5.2 Heterogeneous FTL
6 Datasets and Evaluations
7 Related Surveys
8 Conclusion and Future Directions
8.1 Summary of the Survey
8.2 Future Directions