[steve_g]

It looks like this tool is intended to label _documents_ using rules/heuristics. That seems useful.

My desired use case is to label words or phrases (named entity recognition) - specifically for chemicals. It seems like this tool isn't designed for that. Am I understanding correctly?

[dataqa]

There is a tutorial on the site where you use rules to extract mentions of side effects from forum posts: https://dataqa.ai/docs/tutorials/medical_side_effects/ner_me.... You can use this tool for NER.