Maybe you were referring to the _demo_ of custom training, here: https://visual-recognition-demo.mybluemix.net/train https://visual-recognition-demo.mybluemix.

Maybe you were referring to the _demo_ of custom training, here: https://visual-recognition-demo.mybluemix.net/train https://visual-recognition-demo.mybluemix.net/train ? The demo only classifies using one classifier at a time, but the API can do multiple at once.