Where can I find freely available multi-label datasets online? I'm trying to find multi-label classfication datasets, which are available for free online. 

By "multi-label" I mean that each instance can be labeled with anywhere from a single to $k$ labels, where $k$ is the total number of different labels in the dataset. Typically all information about the labels would be represented in a binary matrix $\mathbf{M}$, where $\mathbf{M}_{ij}=1$ if instance $i$ has label $j$, and $0$ otherwise.

I've found the following two datasets so far:


iMaterialist Challenge (Fashion) at FGVC5 from Kaggle.com
DeliciousMIL: A Data Set for Multi-Label Multi-Instance Learning with Instance Labels Data Set


I've also looked at the Mulan multi-label datasets page, but they are pretty opaquely (and sometimes erroneously) described. 

Where can I find more multi-label datasets (preferably with 20-200 different labels in total)?
Try, Kaggle Toxic Comments Challenge. You have to classify the answer to multiple classes at the same time. It is a multi-label classification problem.