Defining custom words

[Technerder]

I was looking through the project homepage here (http://arjo129.github.io/uSpeech/) and I noticed that higher accuracy could be achieved by using words ("30% - 40% accuracy if based on phonemes, up to 80% if based on words.") yet I was unable to find any information on how to implement custom words.

Where can I find information on implementing custom words (Such as "Hello", "Goodbye", etc)?