title: NLTK Named Entity Recognition with Custom Data
body: <p>I'm trying to extract named entities from my text using NLTK. I find that NLTK NER is not very accurate for my purpose and I want to add some more tags of my own as well. I've been trying to find a way to train my own NER, but I don't seem to be able to find the right resources. 
  I have a couple of questions regarding NLTK-</p>
  
  <ol>
  <li>Can I use my own data to train an Named Entity Recognizer in NLTK?</li>
  <li>If I can train using my own data, is the named_entity.py the file to be modified?</li>
  <li>Does the input file format have to be in IOB eg. Eric NNP B-PERSON ?</li>
  <li>Are there any resources - apart from the nltk cookbook and nlp with python that I can use?</li>
  </ol>
  
  <p>I would really appreciate help in this regard</p>