tokens: When it comes to manipulating the text you want to convert the UTF-8 ( which is not a fixed width ) to an internal fixed width format ; ( UTF-16 or UTF-32 are common formats for manipulation and easy to use ; ( UTF-16 windows , UTF-32 for most * nix like OS ) ) .
ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Operating_System O O O O B-Operating_System I-Operating_System O O O O O