General   (General discussion, talk about anything.)

November explanation:

BBC Green Book

Not to be confused with:

The Green Inkers

EDIT

Regardless of the colour of ink used, it is common to refer to correspondence of any kind (including email and webpages) as being in "green ink", so long as it broadly fits the following identifying characteristics:
- Stridency
- Impertinence
- Unreasonableness
- Unrealism
- Fancifulness
- Obsessiveness

Common comorbid characteristics include IRRELEVANT CAPITALISATION, overuse of exclamation marks!!!!!!!! and veiled threats or warnings directed at the recipient